def __init__(self, instanceName):
"""
Here the Element constructor must be called. Do not connect
internal nodes here.
"""
cir.Element.__init__(self, instanceName)
self.diogs = Junction()
self.diogd = Junction()
def __init__(self, instanceName):
cir.Element.__init__(self, instanceName)
# Use junctions to model diodes and capacitors
self.jif = SVJunction()
self.jir = SVJunction()
self.jile = Junction()
self.jilc = Junction()
# collector/emitter terminal numbers: may be re-mapped by
# extrinsic device
self._ct = 0
self._et = 2
class SVBJTi(cir.Element):
"""
State-variable-based Gummel-Poon intrinsic BJT model based
This implementation based mainly on previous implementation in
carrot and some equations from Pspice manual, with the addition of
the state-variable definitions.
Terminal order: 0 Collector, 1 Base, 2 Emitter, (3 Bulk, not included)::
C (0) o----, 4----o E (2)
\ /
\ /
---------
|
o
B (1)
Can be used for NPN or PNP transistors.
Intrinsic Internal Topology
+++++++++++++++++++++++++++
The state variable formulation is achieved by replacing the BE and
BC diodes (Ibf, Ibr) with state-variable based diodes. This
requires two additional variables (nodes) but eliminates large
positive exponentials from the model::
Term : x2
+--------------------------+
| |
/|\ /^\
( | ) gyr v2 ( | ) gyr vbc(x)
\V/ \|/
tref | |
,----+--------------------------+
| | |
| /^\ /|\
| ( | ) gyr v1 ( | ) gyr vbe(x)
--- \|/ \V/
V | |
+--------------------------+
Term : x1
All currents/charges in the model are functions of voltages v3
(x2) and v4 (x1). Note that vbc and vbe are now also functions of
x1, x2.
In addition we may need 2 additional nodes (plus reference) if rb
is not zero: Bi for the internal base node and tib to measure the
internal base current and calculate Rb(ib).
1. If RB == 0::
+----------------+--o 0 (C)
- | |
/^\ |
v2 ( | ) ibc(x2) |
\|/ |
+ | /|\
(B) 1 o---------+ ( | ) ice(x1,x2)
+ | \V/
/|\ |
v1 ( | ) ibe(x1) |
\V/ |
- | |
+----------------+--o 2 (E)
2. If RB != 0::
+----------------+--o 0 (C)
- | |
/^\ |
gyr tib v2 ( | ) ibc(x2) |
\|/ |
,---, + | /|\
(B) 1 o----( --> )----------+ Term : Bi ( | ) ice(x1,x2)
`---` + | \V/
/|\ |
v1 ( | ) ibe(x1) |
\V/ |
- | |
gyr v(1,Bi) +----------------+--o 2 (E)
,---,
+---( <-- ) -----+
| `---` |
tref | | ib/gyr
,--+ |
| | ,---, | Term : ib
| +---( --> )------+
| `---`
---
V gyr ib Rb(ib)
Charge sources are connected between internal nodes defined
above. If xcjc is not 1 but RB is zero, xcjc is ignored.
"""
devType = "svbjt"
paramDict = dict(
cir.Element.tempItem,
type = ('Type (npn or pnp)', '', str, 'npn'),
isat = ('Transport saturation current', 'A', float, 1e-16),
bf = ('Ideal maximum forward beta', '', float, 100.),
nf = ('Forward current emission coefficient', '', float, 1.),
vaf = ('Forward early voltage', 'V', float, 0.),
ikf = ('Forward-beta high current roll-off knee current', 'A',
float, 0.),
ise = ('Base-emitter leakage saturation current', 'A', float, 0.),
ne = ('Base-emitter leakage emission coefficient', '', float, 1.5),
br = ('Ideal maximum reverse beta', '', float, 1.),
nr = ('Reverse current emission coefficient', '', float, 1.),
var = ('Reverse early voltage', 'V', float, 0.),
ikr = ('Corner for reverse-beta high current roll off', 'A', float, 0.),
isc = ('Base collector leakage saturation current', 'A', float, 0.),
nc = ('Base-collector leakage emission coefficient', '', float, 2.),
rb = ('Zero bias base resistance', 'Ohm', float, 0.),
rbm = ('Minimum base resistance', 'Ohm', float, 0.),
irb = ('Current at which rb falls to half of rbm', 'A', float, 0.),
eg = ('Badgap voltage', 'eV', float, 1.11),
cje = ('Base emitter zero bias p-n capacitance', 'F', float, 0.),
vje = ('Base emitter built in potential', 'V', float, 0.75),
mje = ('Base emitter p-n grading factor', '', float, 0.33),
cjc = ('Base collector zero bias p-n capacitance', 'F', float, 0.),
vjc = ('Base collector built in potential', 'V', float, 0.75),
mjc = ('Base collector p-n grading factor', '', float, 0.33),
xcjc = ('Fraction of cbc connected internal to rb', '', float, 1.),
fc = ('Forward bias depletion capacitor coefficient', '', float, 0.5),
tf = ('Ideal forward transit time', 's', float, 0.),
xtf = ('Transit time bias dependence coefficient', '', float, 0.),
vtf = ('Transit time dependency on vbc', 'V', float, 0.),
itf = ('Transit time dependency on ic', 'A', float, 0.),
tr = ('Ideal reverse transit time', 's', float, 0.),
xtb = ('Forward and reverse beta temperature coefficient', '',
float, 0.),
xti = ('IS temperature effect exponent', '', float, 3.),
tnom = ('Nominal temperature', 'C', float, 27.),
area = ('Current multiplier', '', float, 1.)
)
def __init__(self, instanceName):
cir.Element.__init__(self, instanceName)
# Use junctions to model diodes and capacitors
self.jif = SVJunction()
self.jir = SVJunction()
self.jile = Junction()
self.jilc = Junction()
# collector/emitter terminal numbers: may be re-mapped by
# extrinsic device
self._ct = 0
self._et = 2
def process_params(self):
"""
Adjusts internal topology and makes preliminary calculations
according to parameters.
"""
# Define topology first. Add state variable nodes
x2 = self.add_internal_term('x2','s.v.')
x1 = self.add_internal_term('x1','s.v.')
tref = self.add_reference_term()
# Default configuration assumes rb == 0
# ibe, vbe, ibc, vbc, ice
self.csOutPorts = [(1, self._et), (tref, x1), (1, self._ct),
(tref, x2), (self._ct, self._et)]
# Controling voltages are x1, x2
self.controlPorts = [(x1, tref), (x2, tref)]
# qbe, qbc
self.qsOutPorts = [(1, self._et), (1, self._ct)]
# Flag to signal if the extra charge Qbx is needed or not
self._qbx = False
# Default state-variable VCCSs
self.linearVCCS = [((1, self._et), (x1, tref), glVar.gyr),
((1, self._ct), (x2, tref), glVar.gyr)]
if self.rb != 0.:
# rb is not zero: add internal terminals
tBi = self.add_internal_term('Bi', 'V')
tib = self.add_internal_term('ib', '{0} A'.format(glVar.gyr))
# Add Linear VCCS for gyrator(s)
self.linearVCCS = [((tBi, self._et), (x1, tref), glVar.gyr),
((tBi, 0), (x2, tref), glVar.gyr),
((1, tBi), (tib, tref), glVar.gyr),
((tib, tref), (1, tBi), glVar.gyr)]
# ibe, vbe, ibc, vbc, ice, Rb(ib) * ib
self.csOutPorts = [(tBi, self._et), (tref, x1), (tBi, self._ct),
(tref, x2), (self._ct, self._et), (tref, tib)]
# Controling voltages are x1, x2 and gyrator port
self.controlPorts = [(x1, tref), (x2, tref), (tib, tref)]
# qbie, qbic
self.qsOutPorts = [(tBi, self._et), (tBi, self._ct)]
# Now check if Cjbc must be splitted (since rb != 0)
if (self.cjc != 0.) and (self.xcjc < 1.):
# add extra charge source
self.qsOutPorts.append((1, self._ct))
self._qbx = True
# Make sure the guess is consistent
self.vPortGuess = np.zeros(len(self.controlPorts))
# # Try guess in active region
# self.vPortGuess[0] = 100. # x1
# self.vPortGuess[1] = -1. # x2
# if self.rb != 0.:
# self.vPortGuess[2] = 1e-6 / glVar.gyr # ib
# In principle we may not need any charge
keepPorts = [ ]
if self.cje + self.tf != 0.:
# keep qbe
keepPorts.append(self.qsOutPorts[0])
if self.cjc + self.tr != 0.:
# keep qbc, qbx (if any)
if self._qbx:
keepPorts += self.qsOutPorts[-2:]
else:
keepPorts.append(self.qsOutPorts[-1])
self.qsOutPorts = keepPorts
# keep track of how many output variables are needed
self.ncurrents = len(self.csOutPorts)
self.ncharges = len(self.qsOutPorts)
# NPN or PNP
if self.type == 'pnp':
self._typef = -1.
else:
self._typef = 1.
# Calculate common variables
# Absolute nominal temperature
self.Tnomabs = self.tnom + const.T0
self.egapn = self.eg - .000702 * (self.Tnomabs**2) \
/ (self.Tnomabs + 1108.)
# jif produces if, cje
self.jif.process_params(self.isat, self.nf, self.fc, self.cje,
self.vje, self.mje, self.xti, self.eg,
self.Tnomabs)
# jir produces ir, cjc
self.jir.process_params(self.isat, self.nr, self.fc, self.cjc,
self.vjc, self.mjc, self.xti, self.eg,
self.Tnomabs)
if self.ise != 0.:
# jile produces ile
self.jile.process_params(self.ise, self.ne, 0, 0, 0, 0,
self.xti, self.eg, self.Tnomabs)
if self.isc != 0.:
# jilc produces ilc
self.jilc.process_params(self.isc, self.nc, 0, 0, 0, 0,
self.xti, self.eg, self.Tnomabs)
# Constants needed for rb(ib) calculation
if self.irb != 0.:
self._ck1 = 144. / self.irb / self.area /np.pi/np.pi
self._ck2 = np.pi*np.pi * np.sqrt(self.irb * self.area) / 24.
def set_temp_vars(self, temp):
"""
Calculate temperature-dependent variables, given temp in deg. C
"""
# Absolute temperature (note self.temp is in deg. C)
self.Tabs = const.T0 + temp
# Normalized temp
self.tnratio = self.Tabs / self.Tnomabs
tnXTB = pow(self.tnratio, self.xtb)
# Thermal voltage
self.vt = const.k * self.Tabs / const.q
# Temperature-adjusted egap
self.egap_t = self.eg - .000702 * (self.Tabs**2) / (self.Tabs + 1108.)
# set temperature in juctions
self.jif.set_temp_vars(self.Tabs, self.Tnomabs, self.vt,
self.egapn, self.egap_t)
self.jir.set_temp_vars(self.Tabs, self.Tnomabs, self.vt,
self.egapn, self.egap_t)
# Adjust ise and isc (which have different temperature variation)
if self.ise != 0.:
self.jile.set_temp_vars(self.Tabs, self.Tnomabs, self.vt,
self.egapn, self.egap_t)
self.jile._t_is /= tnXTB
if self.isc != 0.:
self.jilc.set_temp_vars(self.Tabs, self.Tnomabs, self.vt,
self.egapn, self.egap_t)
self.jilc._t_is /= tnXTB
# Now some BJT-only variables
self._bf_t = self.bf * tnXTB
self._br_t = self.br * tnXTB
def eval_cqs(self, vPort):
"""
Calculates currents/charges
Input is a vector may be one of the following, depending on
parameter values::
vPort = [xbe, xbc]
vPort = [xbe, xbc, v4_i] (gyrator voltage, irb != 0)
Output also depends on parameter values. Charges only present
if parameters make them different than 0 (i.e., cje, tf, cjc,
etc. are set to nonzero values)::
iVec = [ibe, vbe, ibc, vbc, ice]
iVec = [ibe, vbe, ibc, vbc, ice, gyr*ib*Rb] (rb != 0)
qVec = [qbe, qbc]
qVec = [qbe, qbc, qbx] (rb != 0 and cjc != 1)
"""
# Invert state variables if needed
vPort1 = self._typef * vPort
# Calculate junctions currents and voltages
(ibf, vbe) = self.jif.get_idvd(vPort1[0])
(ibr, vbc) = self.jir.get_idvd(vPort1[1])
if self.ise != 0.:
ile = self.jile.get_id(vbe)
else:
ile = 0.
if self.isc != 0.:
ilc = self.jilc.get_id(vbc)
else:
ilc = 0.
# Kqb
q1m1 = 1.
if self.var != 0.:
q1m1 -= vbe / self.var
if self.vaf != 0.:
q1m1 -= vbc / self.vaf
kqb = 1. / q1m1
# We need extra checking to consider the following
# possibilities to create the AD tape:
#
# 1. both ikf and ikr are zero -> no tape generated
# 2. One of them is nonzero but both ibf and ibr are zero -> want tape
# but only for the nonzero parameter
if self.ikf + self.ikr != 0.:
q2 = 0.
if self.ikf != 0.:
q2 += ibf / self.ikf
if self.ikr != 0.:
q2 += ibr / self.ikr
kqb *= .5 * (1. + np.sqrt(1. + 4. * q2))
# Create output vector [ibe, ibc, ice, ...]
iVec = np.zeros(self.ncurrents, dtype = type(ibf))
qVec = np.zeros(self.ncharges, dtype = type(ibf))
# ibe, vbe
iVec[0] = ibf / self._bf_t + ile
iVec[1] = glVar.gyr * vbe
# ibc, vbc
iVec[2] = ibr / self._br_t + ilc
iVec[3] = glVar.gyr * vbc
# ice
iVec[4] = (ibf - ibr) / kqb
# RB
if self.rb != 0.:
# Using gyrator
# vPort1[2] not defined if rb == 0
# ib has area effect included (removed by _ck1 and _ck2)
ib = vPort1[2] * glVar.gyr
if self.irb != 0.:
ib1 = np.abs(ib)
x = np.sqrt(1. + self._ck1 * ib1) - 1.
x *= self._ck2 / np.sqrt(ib1)
tx = np.tan(x)
c = self.rbm + 3. * (self.rb - self.rbm) \
* (tx - x) / (x * tx * tx)
rb = ad.condassign(ib1, c, self.rb)
else:
rb = self.rbm + (self.rb - self.rbm) / kqb
# Output is gyr * ib * rb. It is divided by area^2 to
# compensate that the whole vector is multiplied by area
# at the end
iVec[5] = glVar.gyr * ib * rb / pow(self.area, 2)
vbcx = ib * rb / self.area + vbc
# Charges -----------------------------------------------
# Note that if tf == 0 and cje == 0, nothing is calculated and
# nothing is assigned to the output vector.
# qbe is the first charge (0)
if self.tf != 0.:
# Effective tf
tfeff = self.tf
if self.vtf != 0.:
x = ibf / (ibf + self.itf)
# safe_exp() not needed since positive vbc grows
# logarithmically
tfeff *= (1. + self.xtf * x*x *
np.exp(vbc /1.44 /self.vtf))
qVec[0] = tfeff * ibf
if self.cje != 0.:
qVec[0] += self.jif.get_qd(vbe)
# qbc
if self._qbx:
if self.tr != 0.:
qVec[-2] = self.tr * ibr
if self.cjc != 0.:
qVec[-2] += self.jir.get_qd(vbc) * self.xcjc
# qbx
qVec[-1] = self.jir.get_qd(vbcx) * (1. - self.xcjc)
else:
if self.tr != 0.:
qVec[-1] = self.tr * ibr
if self.cjc != 0.:
qVec[-1] += self.jir.get_qd(vbc)
# Consider area effect and invert currents if needed
iVec *= self.area * self._typef
qVec *= self.area * self._typef
return (iVec, qVec)
def power(self, vPort, currV):
"""
Calculate total instantaneous power
Input: control voltages as in eval_cqs() and currents from
returned by eval_cqs()
"""
# vce = vbe - vbc
gyrvce = currV[1] - currV[3]
if self.rb != 0.:
# currV[5] = ib * Rb * gyr
# vPort[2] = ib / gyr
pRb = currV[5] * vPort[2]
else:
pRb = 0.
# pout = ibe * vbie + ibc * vbic + vce * ice + pRb
pout = (currV[0] * currV[1] + currV[2] * currV[3]
+ currV[4] * gyrvce) / glVar.gyr + pRb
return pout
def get_OP(self, vPort):
"""
Calculates operating point information
Input: same as eval_cqs
Output: dictionary with OP variables
For now it is quite incomplete
"""
# First we need the Jacobian
(outV, jac) = self.eval_and_deriv(vPort)
power = self.power(vPort, outV)
# calculate gm, etc. in terms od jac for state-variable
# formulation
opDict = dict(
VBE = outV[1] / glVar.gyr,
VCE = (outV[1] - outV[3]) / glVar.gyr,
IB = outV[0] + outV[2],
IC = outV[4] - outV[2],
IE = - outV[4] - outV[0],
Temp = self.temp,
Power = power,
)
return opDict
def get_noise(self, f):
"""
Return noise spectral density at frequency f
Requires a previous call to get_OP()
Not implemented yet
"""
return None
def __init__(self, instanceName):
IBJT.__init__(self, instanceName)
# Collector-bulk junction
self.cbjtn = Junction()
self.__doc__ += IBJT.__doc__
class BJTi(cir.Element):
"""
Gummel-Poon intrinsic BJT model
This implementation based mainly on previous implementation in
carrot and some equations from Pspice manual.
Terminal order: 0 Collector, 1 Base, 2 Emitter::
C (0) o----, 4----o E (2)
\ /
\ /
---------
|
o
B (1)
Can be used for NPN or PNP transistors.
Intrinsic Internal Topology
+++++++++++++++++++++++++++
Internally may add 2 additional nodes (plus reference) if rb is
not zero: Bi for the internal base node and tib to measure the
internal base current and calculate Rb(ib). The possible
configurations are described here.
1. If RB == 0::
+----------------+--o 0 (C)
| |
/^\ |
( | ) ibc(vbc) |
\|/ |
| /|\
(B) 1 o---------+ ( | ) ice
| \V/
/|\ |
( | ) ibe(vbe) |
\V/ |
| |
+----------------+--o 2 (E)
2. If RB != 0::
+----------------+--o 0 (C)
| |
/^\ |
( | ) ibc(vbc) |
gyr * tib \|/ |
,---, | /|\
(B) 1 o----( --> )----------+ Term : Bi ( | ) ice
`---` | \V/
/|\ |
( | ) ibe(vbe) |
\V/ |
| |
+----------------+--o 2 (E)
gyr v(1,Bi)
,---,
+---( <-- )------+
| `---` |
tref | | voltage: ib/gyr
,---+ |
| | ,---, |
| +---( --> )------+ Term : ib
| `---`
--- gyr ib Rb(ib)
V
Charge sources are connected between internal nodes defined
above. If xcjc is not 1 but RB is zero, xcjc is ignored.
"""
devType = "bjt"
paramDict = dict(
cir.Element.tempItem,
type = ('Type (npn or pnp)', '', str, 'npn'),
isat = ('Transport saturation current', 'A', float, 1e-16),
bf = ('Ideal maximum forward beta', '', float, 100.),
nf = ('Forward current emission coefficient', '', float, 1.),
vaf = ('Forward early voltage', 'V', float, 0.),
ikf = ('Forward-beta high current roll-off knee current', 'A',
float, 0.),
ise = ('Base-emitter leakage saturation current', 'A', float, 0.),
ne = ('Base-emitter leakage emission coefficient', '', float, 1.5),
br = ('Ideal maximum reverse beta', '', float, 1.),
nr = ('Reverse current emission coefficient', '', float, 1.),
var = ('Reverse early voltage', 'V', float, 0.),
ikr = ('Corner for reverse-beta high current roll off', 'A', float, 0.),
isc = ('Base collector leakage saturation current', 'A', float, 0.),
nc = ('Base-collector leakage emission coefficient', '', float, 2.),
rb = ('Zero bias base resistance', 'W', float, 0.),
rbm = ('Minimum base resistance', 'W', float, 0.),
irb = ('Current at which rb falls to half of rbm', 'A', float, 0.),
eg = ('Badgap voltage', 'eV', float, 1.11),
cje = ('Base emitter zero bias p-n capacitance', 'F', float, 0.),
vje = ('Base emitter built in potential', 'V', float, 0.75),
mje = ('Base emitter p-n grading factor', '', float, 0.33),
cjc = ('Base collector zero bias p-n capacitance', 'F', float, 0.),
vjc = ('Base collector built in potential', 'V', float, 0.75),
mjc = ('Base collector p-n grading factor', '', float, 0.33),
xcjc = ('Fraction of cbc connected internal to rb', '', float, 1.),
fc = ('Forward bias depletion capacitor coefficient', '', float, 0.5),
tf = ('Ideal forward transit time', 'S', float, 0.),
xtf = ('Transit time bias dependence coefficient', '', float, 0.),
vtf = ('Transit time dependency on vbc', 'V', float, 0.),
itf = ('Transit time dependency on ic', 'A', float, 0.),
tr = ('Ideal reverse transit time', 'S', float, 0.),
xtb = ('Forward and reverse beta temperature coefficient', '',
float, 0.),
xti = ('IS temperature effect exponent', '', float, 3.),
tnom = ('Nominal temperature', 'C', float, 27.),
area = ('Current multiplier', '', float, 1.)
)
def __init__(self, instanceName):
cir.Element.__init__(self, instanceName)
# Use junctions to model diodes and capacitors
self.jif = Junction()
self.jir = Junction()
self.jile = Junction()
self.jilc = Junction()
# collector/emitter terminal numbers: may be re-mapped by
# extrinsic device
self._ct = 0
self._et = 2
def process_params(self):
"""
Adjusts internal topology and makes preliminary calculations
according to parameters
"""
# Default configuration assumes rb == 0
# ibe, ibc, ice
self.csOutPorts = [(1, self._et), (1, self._ct),
(self._ct, self._et)]
# Controling voltages are vbe, vbc
self.controlPorts = [(1, self._et), (1, self._ct)]
self.vPortGuess = np.array([0., 0.])
# qbe, qbc
self.qsOutPorts = [(1, self._et), (1, self._ct)]
# Define topology first
# Flag to signal if the extra charge Qbx is needed or not
self._qbx = False
if self.rb:
# rb is not zero: add internal terminals
tBi = self.add_internal_term('Bi', 'V')
tib = self.add_internal_term('ib', '{0} A'.format(glVar.gyr))
tref = self.add_reference_term()
# Linear VCCS for gyrator(s)
self.linearVCCS = [((1, tBi), (tib, tref), glVar.gyr),
((tib, tref), (1, tBi), glVar.gyr)]
# ibe, ibc, ice, Rb(ib) * ib
self.csOutPorts = [(tBi, self._et), (tBi, self._ct),
(self._ct, self._et), (tref, tib)]
# Controling voltages are vbie, vbic and gyrator port
self.controlPorts = [(tBi, self._et), (tBi, self._ct),
(tib, tref)]
self.vPortGuess = np.array([0., 0., 0.])
# qbie, qbic
self.qsOutPorts = [(tBi, self._et), (tBi, self._ct)]
# Now check if Cjbc must be splitted (since rb != 0)
if self.cjc and (self.xcjc < 1.):
self.qsOutPorts.append((1, self._ct))
self._qbx = True
# In principle we may not need any charge
keepPorts = [ ]
if self.cje + self.tf:
# keep qbe
keepPorts.append(self.qsOutPorts[0])
if self.cjc + self.tr:
# keep qbc, qbx (if any)
if self._qbx:
keepPorts += self.qsOutPorts[-2:]
else:
keepPorts.append(self.qsOutPorts[-1])
self.qsOutPorts = keepPorts
# keep track of how many output variables are needed
self.ncurrents = len(self.csOutPorts)
self.ncharges = len(self.qsOutPorts)
# NPN or PNP
if self.type == 'pnp':
self._typef = -1.
else:
self._typef = 1.
# Calculate common variables
# Absolute nominal temperature
self.Tnomabs = self.tnom + const.T0
self.egapn = self.eg - .000702 * (self.Tnomabs**2) \
/ (self.Tnomabs + 1108.)
# jif produces if, cje
self.jif.process_params(self.isat, self.nf, self.fc, self.cje,
self.vje, self.mje, self.xti, self.eg,
self.Tnomabs)
# jir produces ir, cjc
self.jir.process_params(self.isat, self.nr, self.fc, self.cjc,
self.vjc, self.mjc, self.xti, self.eg,
self.Tnomabs)
if self.ise:
# jile produces ile
self.jile.process_params(self.ise, self.ne, 0, 0, 0, 0,
self.xti, self.eg, self.Tnomabs)
if self.isc:
# jilc produces ilc
self.jilc.process_params(self.isc, self.nc, 0, 0, 0, 0,
self.xti, self.eg, self.Tnomabs)
# Constants needed for rb(ib) calculation
if self.irb:
self._ck1 = 144. / self.irb / self.area /np.pi/np.pi
self._ck2 = np.pi*np.pi * np.sqrt(self.irb * self.area) / 24.
def set_temp_vars(self, temp):
"""
Calculate temperature-dependent variables, given temp in deg. C
"""
# Absolute temperature (note self.temp is in deg. C)
self.Tabs = const.T0 + temp
# Normalized temp
self.tnratio = self.Tabs / self.Tnomabs
tnXTB = pow(self.tnratio, self.xtb)
# Thermal voltage
self.vt = const.k * self.Tabs / const.q
# Temperature-adjusted egap
self.egap_t = self.eg - .000702 * (self.Tabs**2) / (self.Tabs + 1108.)
# set temperature in juctions
self.jif.set_temp_vars(self.Tabs, self.Tnomabs, self.vt,
self.egapn, self.egap_t)
self.jir.set_temp_vars(self.Tabs, self.Tnomabs, self.vt,
self.egapn, self.egap_t)
# Adjust ise and isc (which have different temperature variation)
if self.ise:
self.jile.set_temp_vars(self.Tabs, self.Tnomabs, self.vt,
self.egapn, self.egap_t)
self.jile._t_is /= tnXTB
if self.isc:
self.jilc.set_temp_vars(self.Tabs, self.Tnomabs, self.vt,
self.egapn, self.egap_t)
self.jilc._t_is /= tnXTB
# Now some BJT-only variables
self._bf_t = self.bf * tnXTB
self._br_t = self.br * tnXTB
def eval_cqs(self, vPort):
"""
Calculates currents/charges
Input is a vector may be one of the following, depending on
parameter values::
vPort = [vbe, vbc]
vPort = [vbie, vbic, v1_i] (gyrator voltage, rb != 0)
Output also depends on parameter values. Charges only present
if parameters make them different than 0 (i.e., cje, tf, cjc,
etc. are set to nonzero values)::
iVec = [ibe, ibc, ice]
iVec = [ibe, ibc, ice, gyr*ib*Rb] (rb != 0)
qVec = [qbe, qbc]
qVec = [qbe, qbc, qbx] (rb != 0 and cjc != 1)
"""
# Invert control voltages if needed
vPort1 = self._typef * vPort
# Calculate regular PN junctions currents and charges
ibf = self.jif.get_id(vPort1[0])
ibr = self.jif.get_id(vPort1[1])
if self.ise:
ile = self.jile.get_id(vPort1[0])
else:
ile = 0.
if self.isc:
ilc = self.jilc.get_id(vPort1[1])
else:
ilc = 0.
# Kqb
q1m1 = 1.
if self.var:
q1m1 -= vPort1[0] / self.var
if self.vaf:
q1m1 -= vPort1[1] / self.vaf
kqb = 1. / q1m1
q2 = 0.
if self.ikf:
q2 += ibf / self.ikf
if self.ikr:
q2 += ibr / self.ikr
if q2:
kqb *= .5 * (1. + np.sqrt(1. + 4. * q2))
# Create output vector [ibe, ibc, ice, ...]
iVec = np.zeros(self.ncurrents, dtype = type(ibf))
qVec = np.zeros(self.ncharges, dtype = type(ibf))
# ibe
iVec[0] = ibf / self._bf_t + ile
# ibc
iVec[1] = ibr / self._br_t + ilc
# ice
iVec[2] = (ibf - ibr) / kqb
# RB
if self.rb:
# Using gyrator
# vPort1[2] not defined if rb == 0
# ib has area effect included (removed by _ck1 and _ck2)
ib = vPort1[2] * glVar.gyr
if self.irb:
ib1 = np.abs(ib)
x = np.sqrt(1. + self._ck1 * ib1) - 1.
x *= self._ck2 / np.sqrt(ib1)
tx = np.tan(x)
c = self.rbm + 3. * (self.rb - self.rbm) \
* (tx - x) / (x * tx * tx)
rb = ad.condassign(ib1, c, self.rb)
else:
rb = self.rbm + (self.rb - self.rbm) / kqb
# Output is gyr * ib * rb. It is divided by area^2 to
# compensate that the whole vector is multiplied by area
# at the end
iVec[3] = glVar.gyr * ib * rb / pow(self.area, 2)
vbcx = ib * rb / self.area + vPort1[1]
# Charges -----------------------------------------------
# Note that if tf == 0 and cje == 0, nothing is calculated and
# nothing is assigned to the output vector.
# qbe is the first charge (0)
if self.tf:
# Effective tf
tfeff = self.tf
if self.vtf:
x = ibf / (ibf + self.itf)
tfeff *= (1. + self.xtf * x*x *
ad.safe_exp(vPort1[1] /1.44 /self.vtf))
qVec[0] = tfeff * ibf
if self.cje:
qVec[0] += self.jif.get_qd(vPort1[0])
# qbc
if self._qbx:
if self.tr:
qVec[-2] = self.tr * ibr
if self.cjc:
qVec[-2] += self.jir.get_qd(vPort1[1]) * self.xcjc
# qbx
qVec[-1] = self.jir.get_qd(vbcx) * (1. - self.xcjc)
else:
if self.tr:
qVec[-1] = self.tr * ibr
if self.cjc:
qVec[-1] += self.jir.get_qd(vPort1[1])
# Consider area effect and invert currents if needed
iVec *= self.area * self._typef
qVec *= self.area * self._typef
return (iVec, qVec)
def power(self, vPort, currV):
"""
Calculate total instantaneous power
Input: control voltages as in eval_cqs() and currents returned
by eval_cqs()
"""
vce = vPort[0] - vPort[1]
if self.rb:
# currV[3] = ib * Rb * gyr
# vPort[2] = ib / gyr
pRb = currV[3] * vPort[2]
else:
pRb = 0.
# pout = ibe * vbie + ibc * vbic + vce * ice + pRb
pout = currV[0] * vPort[0] + currV[1] * vPort[1] \
+ currV[2] * vce + pRb
return pout
def get_OP(self, vPort):
"""
Calculates operating point information
Input: same as eval_cqs
Output: dictionary with OP variables
For now it is quite incomplete
"""
# First we need the Jacobian
(outV, jac) = self.eval_and_deriv(vPort)
self.OP = dict(
VBE = vPort[0],
VCE = vPort[0] - vPort[1],
IB = outV[0] + outV[1],
IC = outV[2] - outV[1],
IE = - outV[2] - outV[0],
gm = jac[2,0] - jac[1,0],
rpi = 1./(jac[0,0] + jac[1,0]),
)
return self.OP
def get_noise(self, f):
"""
Return noise spectral density at frequency f
Requires a previous call to get_OP()
Not implemented yet
"""
return None
class BJT(IBJT):
"""
Bipolar Junction Transistor
---------------------------
This device accepts 3 or 4 terminal connections.
Netlist examples::
bjt:q1 2 3 4 1 model = mypnp isat=4e-17 bf=147 iss=10fA
bjt:q2 2 3 4 model = mypnp isat=4e-17 bf=147 vaf=80 ikf=4m
svbjt:q3 2 3 4 1 model = mypnp vaf=80 ikf=4m iss=15fA
# Electro-thermal versions
bjt_t:q2 2 3 5 1 pout gnd model = mypnp
svbjt_t:q3 2 3 5 1 pout gnd model = mypnp
# Model statement
.model mypnp bjt_t (type=pnp isat=5e-17 cje=60fF vje=0.83 mje=0.35)
Extrinsic Internal Topology
+++++++++++++++++++++++++++
RC, RE and a Collector-Bulk connection are added to intrinsic
BJT models::
RC Term: ct Term: et RE
C (0) o---/\/\/\/--+-----, 4----/\/\/\/----o E (2)
| \ /
| \ /
----- ---------
/ \ |
/ \ o
-----
| B (1)
o Bulk (3)
If RE or RC are zero the internal nodes (ct, et) are not
created. If only 3 connections are specified then the
Bulk-Collector junction is not connected.
Important Note
++++++++++++++
This implementation does not account for the power dissipation
in RE, RC. Use external thermal resistors if that is needed.
Intrinsic Model Information
+++++++++++++++++++++++++++
"""
# Additional documentation
extraDoc = IBJT.__doc__
# Create electrothermal device
makeAutoThermal = True
isNonlinear = True
# Device category
category = "Semiconductor devices"
# devtype is the 'model' name: remove the 'i' from intrinsic name
devType = IBJT.devType
# Do not set numTerms to allow 3 or 4 terminals to be connected
paramDict = dict(
IBJT.paramDict.items(),
re = ('Emitter ohmic resistance', 'W', float, 0.),
rc = ('Collector ohmic resistance', 'W', float, 0.),
cjs = ('Collector substrate capacitance', 'F', float, 0.),
mjs = ('substrate junction exponential factor', '', float, 0.),
vjs = ('substrate junction built in potential', 'V', float, 0.75),
ns = ('substrate p-n coefficient', '', float, 1.),
iss = ('Substrate saturation current', 'A', float, 1e-14)
)
def __init__(self, instanceName):
IBJT.__init__(self, instanceName)
# Collector-bulk junction
self.cbjtn = Junction()
self.__doc__ += IBJT.__doc__
def process_params(self, thermal = False):
# Remove tape if present
ad.delete_tape(self)
if thermal:
extraTerms = 2
else:
extraTerms = 0
# First check external connections
if self.numTerms == 3 + extraTerms:
self.__addCBjtn = False
elif self.numTerms == 4 + extraTerms:
self.__addCBjtn = True
else:
raise cir.CircuitError(
'{0}: Wrong number of connections. \
Can only be {1} or {2}, {3} found.'.format(self.nodeName,
3 + extraTerms,
4 + extraTerms,
self.numTerms))
# Remove internal terminals
self.clean_internal_terms()
# Tell autothermal to re-generate thermal ports
self.__addThermalPorts = True
extraVCCS = list()
if self.re:
# Add et node and translate port descriptions
self._et = self.add_internal_term('et', 'V')
extraVCCS += [((2, self._et), (2, self._et),
self.area / self.re)]
if self.rc:
# Add ct node and translate port descriptions
self._ct = self.add_internal_term('ct', 'V')
extraVCCS += [((0, self._ct), (0, self._ct),
self.area / self.rc)]
# Process parameters from intrinsic device: emitter and
# collector terminals are already substituted.
IBJT.process_params(self)
# Calculate variables in junction
self.cbjtn.process_params(self.iss, self.ns, self.fc, self.cjs,
self.vjs, self.mjs, self.xti, self.eg,
self.Tnomabs)
# Add RE, RC resistors (if any)
self.linearVCCS += extraVCCS
if self.__addCBjtn:
# Add bulk-collector junction
self.__bccn = len(self.controlPorts)
self.__bcon = len(self.csOutPorts)
self.controlPorts.append((3, self._ct))
self.csOutPorts.append((3, self._ct))
if self.cjs:
self.qsOutPorts.append((3, self._ct))
# Initial guess for input ports:
try:
if len(self.vPortGuess) < len(self.controlPorts):
self.vPortGuess = np.concatenate(
(self.vPortGuess, [1]), axis=0)
except AttributeError:
# Ignore if vPortGuess not provided
pass
# Adjust temperature
self.set_temp_vars(self.temp)
def set_temp_vars(self, temp):
"""
Calculate temperature-dependent variables, given temp in deg. C
"""
# Remove tape if present
ad.delete_tape(self)
# First calculate variables from base class
IBJT.set_temp_vars(self, temp)
# Adjust collector-bulk junction temperature
self.cbjtn.set_temp_vars(self.Tabs, self.Tnomabs, self.vt,
self.egapn, self.egap_t)
def eval_cqs(self, vPort, saveOP = False):
"""
vPort is a vector with control voltages
"""
if self.__addCBjtn:
# calculate currents and charges in base class
(iVec1, qVec1) = IBJT.eval_cqs(self, vPort)
# Add contribution of substrate. Ignore extra control
# ports only used for power calculation
v1 = vPort[self.__bccn] * self._typef
isub = self.cbjtn.get_id(v1) * self.area * self._typef
iVec = np.concatenate((iVec1, [isub]), axis = 0)
if self.cjs:
qsub = self.cbjtn.get_qd(v1) * self.area * self._typef
qVec = np.concatenate((qVec1, [qsub]), axis = 0)
else:
qVec = qVec1
return (iVec, qVec)
else:
return IBJT.eval_cqs(self, vPort)
# Create these using the AD facility
eval_and_deriv = ad.eval_and_deriv
eval = ad.eval
def power(self, vPort, currV):
"""
Calculate total instantaneous power
Power in RE, RC not considered.
Input: control voltages as in eval_cqs() and currents
returned by eval_cqs()
"""
pout = IBJT.power(self, vPort, currV)
if self.__addCBjtn:
# add power from substrate junction (RE, RC not counted)
pout += vPort[self.__bccn] * currV[self.__bcon]
return pout
class Device(cir.Element):
"""
Cubic Curtice-Ettemberg Intrinsic MESFET Model
----------------------------------------------
Model derived from fREEDA 1.4 MesfetCT model adapted to re-use
junction code from ``diode.py``. Some parameter names have been
changed: ``isat``, ``tau``. Uses symmetric diodes and
capacitances. Works in reversed mode.
Terminal order: 0 Drain, 1 Gate, 2 Source::
Drain 0
o
|
|
|---+
|
Gate 1 o---->|
|
|---+
|
|
o
Source 2
Netlist example::
mesfetc:m1 2 3 4 a0=0.09910 a1=0.08541 a2=-0.02030 a3=-0.01543
Internal Topology::
,----------------,------------,--o 0 (D)
| | |
/^\ | |
( | ) igd(Vgd) ----- Cgd |
\|/ ----- |
| | /|\
(G) 1 o----+----------------, ( | ) ids(Vgs, Vgd)
| | \V/
/|\ | |
( | ) igs(Vgs) ----- Cgs |
\V/ ----- |
| | |
`----------------'------------'--o 2 (S)
"""
# Device category
category = "Semiconductor devices"
devType = "mesfetc"
paramDict = dict(
cir.Element.tempItem,
a0=("Drain saturation current for Vgs=0", "A", float, 0.1),
a1=("Coefficient for V1", "A/V", float, 0.05),
a2=("Coefficient for V1^2", "A/V^2", float, 0.0),
a3=("Coefficient for V1^3", "A/V^3", float, 0.0),
beta=("V1 dependance on Vds", "1/V", float, 0.0),
vds0=("Vds at which BETA was measured", "V", float, 4.0),
gama=("Slope of drain characteristic in the linear region", "1/V", float, 1.5),
vt0=(
"Voltage at which the channel current is forced to be zero\
for Vgs<=Vto",
"V",
float,
-np.inf,
),
cgs0=("Gate-source Schottky barrier capacitance for Vgs=0", "F", float, 0.0),
cgd0=("Gate-drain Schottky barrier capacitance for Vgd=0", "F", float, 0.0),
isat=("Diode saturation current", "A", float, 0.0),
n=("Diode ideality factor", "", float, 1.0),
ib0=("Breakdown current parameter", "A", float, 0.0),
nr=("Breakdown ideality factor", "", float, 10.0),
vbd=("Breakdown voltage", "V", float, np.inf),
tau=("Channel transit time", "s", float, 0.0),
vbi=("Built-in potential of the Schottky junctions", "V", float, 0.8),
fcc=("Forward-bias depletion capacitance coefficient", "V", float, 0.5),
tnom=("Nominal temperature", "C", float, 27.0),
avt0=("Pinch-off voltage (VP0 or VT0) linear temp. coefficient", "1/K", float, 0.0),
bvt0=("Pinch-off voltage (VP0 or VT0) quadratic temp. coefficient", "1/K^2", float, 0.0),
tbet=("BETA power law temperature coefficient", "1/K", float, 0),
tm=("Ids linear temp. coeff.", "1/K", float, 0.0),
tme=("Ids power law temp. coeff.", "1/K^2", float, 0.0),
eg0=("Barrier height at 0 K", "eV", float, 0.8),
mgs=("Gate-source grading coefficient", "", float, 0.5),
mgd=("Gate-drain grading coefficient", "", float, 0.5),
xti=("Diode saturation current temperature exponent", "", float, 2.0),
area=("Area multiplier", "", float, 1.0),
)
numTerms = 3
# Create electrothermal device
makeAutoThermal = True
isNonlinear = True
nDelays = 2
# igs, igd, ids
csOutPorts = [(1, 2), (1, 0), (0, 2)]
# Controling voltages are Vgs, Vgd
controlPorts = [(1, 2), (1, 0)]
# Time-delayed control port added later. Guess includes time-delayed port
vPortGuess = np.array([0.0, 0.0, 0.0, 0.0])
# charge sources
qsOutPorts = [(1, 2), (1, 0)]
def __init__(self, instanceName):
"""
Here the Element constructor must be called. Do not connect
internal nodes here.
"""
cir.Element.__init__(self, instanceName)
self.diogs = Junction()
self.diogd = Junction()
def process_params(self, thermal=False):
# Called once the external terminals have been connected and
# the non-default parameters have been set. Make sanity checks
# here. Internal terminals/devices should also be defined
# here. Raise cir.CircuitError if a fatal error is found.
ad.delete_tape(self)
# Time-delayed control port
self.delayedContPorts = [(1, 2, self.tau), (1, 0, self.tau)]
# Absolute nominal temperature
self.Tnomabs = self.tnom + const.T0
self.egapn = self.eg0 - 0.000702 * (self.Tnomabs ** 2) / (self.Tnomabs + 1108.0)
# Calculate variables in junctions
self.diogs.process_params(
self.isat, self.n, self.fcc, self.cgs0, self.vbi, self.mgs, self.xti, self.eg0, self.Tnomabs
)
self.diogd.process_params(
self.isat, self.n, self.fcc, self.cgd0, self.vbi, self.mgd, self.xti, self.eg0, self.Tnomabs
)
if not thermal:
# Calculate temperature-dependent variables
self.set_temp_vars(self.temp)
def set_temp_vars(self, temp):
"""
Calculate temperature-dependent variables, given temp in deg. C
"""
ad.delete_tape(self)
# Absolute temperature (note self.temp is in deg. C)
self.Tabs = const.T0 + temp
# Thermal voltage
self.vt = const.k * self.Tabs / const.q
# Temperature-adjusted egap
self.egap_t = self.eg0 - 0.000702 * (self.Tabs ** 2) / (self.Tabs + 1108.0)
# Everything else is handled by junctions
self.diogs.set_temp_vars(self.Tabs, self.Tnomabs, self.vt, self.egapn, self.egap_t)
self.diogd.set_temp_vars(self.Tabs, self.Tnomabs, self.vt, self.egapn, self.egap_t)
delta_T = temp - self.tnom
self._k6 = self.nr * self.vt
self._Vt0 = self.vt0 * (1.0 + (delta_T * self.avt0) + (delta_T ** 2 * self.bvt0))
if self.tbet:
self._Beta = self.beta * pow(1.01, (delta_T * self.tbet))
else:
self._Beta = self.beta
if self.tme and self.tm:
self._idsFac = pow((1.0 + delta_T * self.tm), self.tme)
else:
self._idsFac = 1.0
def eval_cqs(self, vPort, saveOP=False):
"""
Calculates gate and drain current. Input is a vector as follows:
vPort = [vgs(t), vgd(t), vgs(t-tau), vgd(t-tau)]
saveOP has no effect for now
"""
# Calculate junction currents
igs = self.diogs.get_id(vPort[0])
qgs = self.diogs.get_qd(vPort[0])
igd = self.diogd.get_id(vPort[1])
qgd = self.diogd.get_qd(vPort[1])
# Add breakdown current
igs -= self.ib0 * np.exp(-(vPort[0] + self.vbd) / self._k6)
igd -= self.ib0 * np.exp(-(vPort[1] + self.vbd) / self._k6)
DtoSswap = ad.condassign(vPort[0] - vPort[1], 1.0, -1.0)
vds = DtoSswap * (vPort[0] - vPort[1])
vgsi = ad.condassign(DtoSswap, vPort[0], vPort[1])
vgsiT = ad.condassign(DtoSswap, vPort[2], vPort[3])
# Calculate ids.
vx = vgsiT * (1.0 + self._Beta * (self.vds0 - vds))
ids = (self.a0 + vx * (self.a1 + vx * (self.a2 + vx * self.a3))) * np.tanh(self.gama * vds) * self._idsFac
# vgsiT makes more sense than vgsi below? (vgsi in original doc)
ids = ad.condassign((vgsi - self._Vt0), ids, 0.0)
# Must ensure ids > 0 for power conservation
ids = ad.condassign(ids, ids, 0.0)
# Return numpy array with one element per current source.
iVec = np.array([igs, igd, ids * DtoSswap]) * self.area
qVec = np.array([qgs, qgd]) * self.area
return (iVec, qVec)
# Use AD for eval and deriv function
eval_and_deriv = ad.eval_and_deriv
eval = ad.eval
# get_op_vars = ad.get_op_vars
def power(self, vPort, currV):
"""
Calculate total instantaneous power
Input: control voltages and currents from eval_cqs()
"""
vds = vPort[0] - vPort[1]
# pout = vds*ids + vgs*igs + vgd*igd
pout = vds * currV[2] + vPort[0] * currV[0] + vPort[1] * currV[1]
return pout
def get_OP(self, vPort):
"""
Calculates operating point information
Input: vPort = [vgs , vgd , vgs]
Output: dictionary with OP variables
"""
# First we need the Jacobian
(outV, jac) = self.eval_and_deriv(vPort)
# opV = self.get_op_vars(vPort)
self.OP = dict(VGS=vPort[0], VDS=vPort[0] - vPort[1], IDS=outV[2], IGS=outV[0], IGD=outV[1])
return self.OP
def get_noise(self, f):
"""
Return noise spectral density at frequency f
Requires a previous call to get_OP()
Not implemented yet
"""
return None
class ExtMOS(IMOS):
"""
Extrinsic Silicon MOSFET
------------------------
Extrinsic Internal Topology
+++++++++++++++++++++++++++
The model adds the following to the intrinsic model (for NMOS)::
o D (0)
|
\
Cgdo / Rd Drain/source area plus
\ sidewall model
|| |-----------,-----,
,------||------------| | |
| || | ----- -----
| ||--- ----- / \
| || | -----
G (1) o---+----------------||<-------------+-----+------o B (3)
| || | -----
| ||--- ----- \ /
| || | ----- -----
`------||------------| | |
|| |-----------'-----'
\
Cgso / Rs
\
|
o S (2)
Note: electrothermal implementation (if any) does not account for
the power dissipation in Rd and Rs. Use external thermal resistors
if that is needed.
"""
# devtype is the 'model' name: remove the '_i' from intrinsic name
devType = 'mos' + IMOS.devType.split('_i')[0]
# Additional documentation
extraDoc = """
Netlist examples
++++++++++++++++
The model accepts extrinsic plus intrinsic parameters (only
extrinsic parameters shown in example)::
{0}:m1 2 3 4 gnd w=10u l=1u asrc=4e-12 ps=8e=12 model=nch
{0}:m2 4 5 6 6 w=30e-6 l=1e-6 pd=8u ps=16u type=p
.model nch {0} (type=n js=1e-3 cj=2e-4 cjsw=1n)
Intrinsic model
+++++++++++++++
See **{1}** intrinsic model documentation.
""".format(devType, IMOS.devType)
paramDict = dict(
IMOS.paramDict.items(),
m = ('Parallel multiplier', '', float, 1.),
cgdo = ('Gate-drain overlap capacitance per meter channel width',
'F/m', float, 0.),
cgso = ('Gate-source overlap capacitance per meter channel width',
'F/m', float, 0.),
cgbo = ('Gate-bulk overlap capacitance per meter channel length',
'F/m', float, 0.),
rsh = ('Drain and source diffusion sheet resistance',
'Ohm/square', float, 0.),
js = ('Source drain junction current density', 'A/m^2', float, 0.),
jssw = ('Source drain sidewall junction current density',
'A/m', float, 0.),
pb = ('Built in potential of source drain junction',
'V', float, .8),
mj = ('Grading coefficient of source drain junction',
'', float, .5),
pbsw = ('Built in potential of source, drain junction sidewall',
'V', float, .8),
mjsw = ('Grading coefficient of source drain junction sidewall',
'', float, .33),
cj = ('Source drain junction capacitance per unit area',
'F/m^2', float, 0.),
cjsw = (
'Source drain junction sidewall capacitance per unit length',
'F/m', float, 0.),
ad = ('Drain area', 'm^2', float, 0.),
asrc = ('Source area', 'm^2', float, 0.),
pd = ('Drain perimeter', 'm', float, 0.),
ps = ('Source perimeter', 'm', float, 0.),
nrd = ('Number of squares in drain', 'squares', float, 1.),
nrs = ('Number of squares in source', 'squares', float, 1.),
fc = ('Coefficient for forward-bias depletion capacitances', ' ',
float, .5),
xti = ('Junction saturation current temperature exponent', '',
float, 3.),
eg0 = ('Energy bandgap', 'eV', float, 1.11)
)
def __init__(self, instanceName):
IMOS.__init__(self, instanceName)
self.__doc__ += IMOS.__doc__
def process_params(self, thermal = False):
# Remove tape if present
ad.delete_tape(self)
# Remove internal terminals (there should be none created
# by intrinsic model)
self.clean_internal_terms()
# Tell autothermal (if used) to re-generate thermal ports
self.__addThermalPorts = True
# By default drain and source are terminals 0 and 2
self.__di = 0
self.__si = 2
# Resistances
extraVCCS = list()
if self.rsh:
if self.nrd:
# Drain resistor
self.__di = self.add_internal_term('di', 'V')
extraVCCS += [((0, self.__di), (0, self.__di),
1. / self.rsh / self.nrd)]
if self.nrs:
# Source resistor
self.__si = self.add_internal_term('si', 'V')
extraVCCS += [((2, self.__si), (2, self.__si),
1. / self.rsh / self.nrs)]
# Linear capacitances
extraVCQS = list()
if self.cgdo:
# Gate-drain ovelrlap cap
extraVCQS += [((1, self.__di), (1, self.__di),
self.cgdo * self.w)]
if self.cgso:
# Gate-source ovelrlap cap
extraVCQS += [((1, self.__si), (1, self.__si),
self.cgso * self.w)]
if self.cgbo:
# Gate-bulk ovelrlap cap
extraVCQS += [((1, 3), (1, 3),
self.cgbo * self.l)]
# Add extra linear resistors/caps (if any)
self.linearVCCS = extraVCCS
self.linearVCQS = extraVCQS
# Override nonlinear port specs if needed
if extraVCCS:
# Ids, Idb, Isb
self.csOutPorts = [(self.__di, self.__si), (self.__di, 3),
(self.__si, 3)]
# Controling voltages are DB, GB and SB
self.controlPorts = [(self.__di, 3), (1, 3), (self.__si, 3)]
# One charge source connected to each D, G, S
self.qsOutPorts = [(self.__di, 3), (1, 3), (self.__si, 3)]
# Calculate some variables (that may also be calculated in
# intrinsic model)
self.__Tnabs = const.T0 + self.tnom
self.__egapn = self.eg0 - .000702 * (self.__Tnabs**2) \
/ (self.__Tnabs + 1108.)
# Initialize variables in junctions
if self.ad:
self.dj = Junction()
self.dj.process_params(isat = self.js * self.ad,
cj0 = self.cj * self.ad,
vj = self.pb, m = self.mj,
n = 1., fc = self.fc,
xti = self.xti, eg0 = self.eg0,
Tnomabs = self.__Tnabs)
if self.asrc:
self.sj = Junction()
self.sj.process_params(isat = self.js * self.asrc,
cj0 = self.cj * self.asrc,
vj = self.pb, m = self.mj,
n = 1., fc = self.fc,
xti = self.xti, eg0 = self.eg0,
Tnomabs = self.__Tnabs)
if self.pd:
self.djsw = Junction()
self.djsw.process_params(isat = self.jssw * self.pd,
cj0 = self.cjsw * self.pd,
vj = self.pbsw, m = self.mjsw,
n = 1., fc = self.fc,
xti = self.xti, eg0 = self.eg0,
Tnomabs = self.__Tnabs)
if self.ps:
self.sjsw = Junction()
self.sjsw.process_params(isat = self.jssw * self.ps,
cj0 = self.cjsw * self.ps,
vj = self.pbsw, m = self.mjsw,
n = 1., fc = self.fc,
xti = self.xti, eg0 = self.eg0,
Tnomabs = self.__Tnabs)
# Process parameters from intrinsic device:
# set_temp_vars() called there
IMOS.process_params(self)
def set_temp_vars(self, temp):
"""
Calculate temperature-dependent variables, given temp in deg. C
"""
# Remove tape if present
ad.delete_tape(self)
# First calculate variables from base class
IMOS.set_temp_vars(self, temp)
# Absolute temperature
Tabs = temp + const.T0
# Temperature-adjusted egap
egap_t = self.eg0 - .000702 * (Tabs**2) / (Tabs + 1108.)
# Thermal voltage
Vt = const.k * Tabs / const.q
# Adjust junction temperatures
if self.ad:
self.dj.set_temp_vars(Tabs, self.__Tnabs, Vt,
self.__egapn, egap_t)
if self.pd:
self.djsw.set_temp_vars(Tabs, self.__Tnabs, Vt,
self.__egapn, egap_t)
if self.asrc:
self.sj.set_temp_vars(Tabs, self.__Tnabs, Vt,
self.__egapn, egap_t)
if self.ps:
self.sjsw.set_temp_vars(Tabs, self.__Tnabs, Vt,
self.__egapn, egap_t)
def eval_cqs(self, vPort, saveOP = False):
"""
vPort is a vector with control voltages
"""
# calculate currents and charges in base class
if saveOP:
(iVec, qVec, opVec) = IMOS.eval_cqs(self, vPort, saveOP)
else:
(iVec, qVec) = IMOS.eval_cqs(self, vPort)
# Add contribution drain diode
v1 = -vPort[0] * self._tf
if self.ad:
# substract to idb
iVec[1] -= self.dj.get_id(v1) * self._tf
if self.cj:
# substract to qd
qVec[0] -= self.dj.get_qd(v1) * self._tf
if self.pd:
# substract to idb
iVec[1] -= self.djsw.get_id(v1) * self._tf
if self.cjsw:
qVec[0] -= self.djsw.get_qd(v1) * self._tf
# Add contribution source diode
v1 = -vPort[2] * self._tf
if self.asrc:
# substract to isb
iVec[2] -= self.sj.get_id(v1) * self._tf
if self.cj:
# substract to qs
qVec[2] -= self.sj.get_qd(v1) * self._tf
if self.ps:
# substract to isb
iVec[2] -= self.sjsw.get_id(v1) * self._tf
if self.cjsw:
qVec[2] -= self.sjsw.get_qd(v1) * self._tf
# Apply parallel multiplier
iVec *= self.m
qVec *= self.m
if saveOP:
return (iVec, qVec, opVec)
else:
return (iVec, qVec)
# Create these using the AD facility
eval_and_deriv = ad.eval_and_deriv
eval = ad.eval
def power(self, vPort, currV):
"""
Calculate total instantaneous power
Power in RE, RC not considered.
Input: control voltages as in eval_cqs() and currents
returned by eval_cqs()
"""
pout = IMOS.power(self, vPort, currV)
if self.__addCBjtn:
# add power from substrate junction and RE, RC
pout += vPort[self.__bccn] * currV[self.__bcon]
return pout
def process_params(self, thermal = False):
# Remove tape if present
ad.delete_tape(self)
# Remove internal terminals (there should be none created
# by intrinsic model)
self.clean_internal_terms()
# Tell autothermal (if used) to re-generate thermal ports
self.__addThermalPorts = True
# By default drain and source are terminals 0 and 2
self.__di = 0
self.__si = 2
# Resistances
extraVCCS = list()
if self.rsh:
if self.nrd:
# Drain resistor
self.__di = self.add_internal_term('di', 'V')
extraVCCS += [((0, self.__di), (0, self.__di),
1. / self.rsh / self.nrd)]
if self.nrs:
# Source resistor
self.__si = self.add_internal_term('si', 'V')
extraVCCS += [((2, self.__si), (2, self.__si),
1. / self.rsh / self.nrs)]
# Linear capacitances
extraVCQS = list()
if self.cgdo:
# Gate-drain ovelrlap cap
extraVCQS += [((1, self.__di), (1, self.__di),
self.cgdo * self.w)]
if self.cgso:
# Gate-source ovelrlap cap
extraVCQS += [((1, self.__si), (1, self.__si),
self.cgso * self.w)]
if self.cgbo:
# Gate-bulk ovelrlap cap
extraVCQS += [((1, 3), (1, 3),
self.cgbo * self.l)]
# Add extra linear resistors/caps (if any)
self.linearVCCS = extraVCCS
self.linearVCQS = extraVCQS
# Override nonlinear port specs if needed
if extraVCCS:
# Ids, Idb, Isb
self.csOutPorts = [(self.__di, self.__si), (self.__di, 3),
(self.__si, 3)]
# Controling voltages are DB, GB and SB
self.controlPorts = [(self.__di, 3), (1, 3), (self.__si, 3)]
# One charge source connected to each D, G, S
self.qsOutPorts = [(self.__di, 3), (1, 3), (self.__si, 3)]
# Calculate some variables (that may also be calculated in
# intrinsic model)
self.__Tnabs = const.T0 + self.tnom
self.__egapn = self.eg0 - .000702 * (self.__Tnabs**2) \
/ (self.__Tnabs + 1108.)
# Initialize variables in junctions
if self.ad:
self.dj = Junction()
self.dj.process_params(isat = self.js * self.ad,
cj0 = self.cj * self.ad,
vj = self.pb, m = self.mj,
n = 1., fc = self.fc,
xti = self.xti, eg0 = self.eg0,
Tnomabs = self.__Tnabs)
if self.asrc:
self.sj = Junction()
self.sj.process_params(isat = self.js * self.asrc,
cj0 = self.cj * self.asrc,
vj = self.pb, m = self.mj,
n = 1., fc = self.fc,
xti = self.xti, eg0 = self.eg0,
Tnomabs = self.__Tnabs)
if self.pd:
self.djsw = Junction()
self.djsw.process_params(isat = self.jssw * self.pd,
cj0 = self.cjsw * self.pd,
vj = self.pbsw, m = self.mjsw,
n = 1., fc = self.fc,
xti = self.xti, eg0 = self.eg0,
Tnomabs = self.__Tnabs)
if self.ps:
self.sjsw = Junction()
self.sjsw.process_params(isat = self.jssw * self.ps,
cj0 = self.cjsw * self.ps,
vj = self.pbsw, m = self.mjsw,
n = 1., fc = self.fc,
xti = self.xti, eg0 = self.eg0,
Tnomabs = self.__Tnabs)
# Process parameters from intrinsic device:
# set_temp_vars() called there
IMOS.process_params(self)
class Device(cir.Element):
"""
Cubic Curtice-Ettemberg Intrinsic MESFET Model
----------------------------------------------
Model derived from fREEDA 1.4 MesfetCT model adapted to re-use
junction code from ``diode.py``. Some parameter names have been
changed: ``isat``, ``tau``. Uses symmetric diodes and
capacitances. Works in reversed mode.
Terminal order: 0 Drain, 1 Gate, 2 Source::
Drain 0
o
|
|
|---+
|
Gate 1 o---->|
|
|---+
|
|
o
Source 2
Netlist example::
mesfetc:m1 2 3 4 a0=0.09910 a1=0.08541 a2=-0.02030 a3=-0.01543
Internal Topology::
,----------------,------------,--o 0 (D)
| | |
/^\ | |
( | ) igd(Vgd) ----- Cgd |
\|/ ----- |
| | /|\
(G) 1 o----+----------------, ( | ) ids(Vgs, Vgd)
| | \V/
/|\ | |
( | ) igs(Vgs) ----- Cgs |
\V/ ----- |
| | |
`----------------'------------'--o 2 (S)
"""
# Device category
category = "Semiconductor devices"
devType = "mesfetc"
paramDict = dict(
cir.Element.tempItem,
a0=('Drain saturation current for Vgs=0', 'A', float, 0.1),
a1=('Coefficient for V1', 'A/V', float, 0.05),
a2=('Coefficient for V1^2', 'A/V^2', float, 0.),
a3=('Coefficient for V1^3', 'A/V^3', float, 0.),
beta=('V1 dependance on Vds', '1/V', float, 0.),
vds0=('Vds at which BETA was measured', 'V', float, 4.),
gama=('Slope of drain characteristic in the linear region', '1/V',
float, 1.5),
vt0=('Voltage at which the channel current is forced to be zero\
for Vgs<=Vto', 'V', float, -np.inf),
cgs0=('Gate-source Schottky barrier capacitance for Vgs=0', 'F', float,
0.),
cgd0=('Gate-drain Schottky barrier capacitance for Vgd=0', 'F', float,
0.),
isat=('Diode saturation current', 'A', float, 0.),
n=('Diode ideality factor', '', float, 1.),
ib0=('Breakdown current parameter', 'A', float, 0.),
nr=('Breakdown ideality factor', '', float, 10.),
vbd=('Breakdown voltage', 'V', float, np.inf),
tau=('Channel transit time', 's', float, 0.),
vbi=('Built-in potential of the Schottky junctions', 'V', float, 0.8),
fcc=('Forward-bias depletion capacitance coefficient', 'V', float,
0.5),
tnom=('Nominal temperature', 'C', float, 27.),
avt0=('Pinch-off voltage (VP0 or VT0) linear temp. coefficient', '1/K',
float, 0.),
bvt0=('Pinch-off voltage (VP0 or VT0) quadratic temp. coefficient',
'1/K^2', float, 0.),
tbet=('BETA power law temperature coefficient', '1/K', float, 0),
tm=('Ids linear temp. coeff.', '1/K', float, 0.),
tme=('Ids power law temp. coeff.', '1/K^2', float, 0.),
eg0=('Barrier height at 0 K', 'eV', float, 0.8),
mgs=('Gate-source grading coefficient', '', float, 0.5),
mgd=('Gate-drain grading coefficient', '', float, 0.5),
xti=('Diode saturation current temperature exponent', '', float, 2.),
area=('Area multiplier', '', float, 1.),
)
numTerms = 3
# Create electrothermal device
makeAutoThermal = True
isNonlinear = True
nDelays = 2
# igs, igd, ids
csOutPorts = [(1, 2), (1, 0), (0, 2)]
# Controling voltages are Vgs, Vgd
controlPorts = [(1, 2), (1, 0)]
# Time-delayed control port added later. Guess includes time-delayed port
vPortGuess = np.array([0., 0., 0., 0.])
# charge sources
qsOutPorts = [(1, 2), (1, 0)]
def __init__(self, instanceName):
"""
Here the Element constructor must be called. Do not connect
internal nodes here.
"""
cir.Element.__init__(self, instanceName)
self.diogs = Junction()
self.diogd = Junction()
def process_params(self, thermal=False):
# Called once the external terminals have been connected and
# the non-default parameters have been set. Make sanity checks
# here. Internal terminals/devices should also be defined
# here. Raise cir.CircuitError if a fatal error is found.
ad.delete_tape(self)
# Time-delayed control port
self.delayedContPorts = [(1, 2, self.tau), (1, 0, self.tau)]
# Absolute nominal temperature
self.Tnomabs = self.tnom + const.T0
self.egapn = self.eg0 - .000702 * (self.Tnomabs**2) \
/ (self.Tnomabs + 1108.)
# Calculate variables in junctions
self.diogs.process_params(self.isat, self.n, self.fcc, self.cgs0,
self.vbi, self.mgs, self.xti, self.eg0,
self.Tnomabs)
self.diogd.process_params(self.isat, self.n, self.fcc, self.cgd0,
self.vbi, self.mgd, self.xti, self.eg0,
self.Tnomabs)
if not thermal:
# Calculate temperature-dependent variables
self.set_temp_vars(self.temp)
def set_temp_vars(self, temp):
"""
Calculate temperature-dependent variables, given temp in deg. C
"""
ad.delete_tape(self)
# Absolute temperature (note self.temp is in deg. C)
self.Tabs = const.T0 + temp
# Thermal voltage
self.vt = const.k * self.Tabs / const.q
# Temperature-adjusted egap
self.egap_t = self.eg0 - .000702 * (self.Tabs**2) / (self.Tabs + 1108.)
# Everything else is handled by junctions
self.diogs.set_temp_vars(self.Tabs, self.Tnomabs, self.vt, self.egapn,
self.egap_t)
self.diogd.set_temp_vars(self.Tabs, self.Tnomabs, self.vt, self.egapn,
self.egap_t)
delta_T = temp - self.tnom
self._k6 = self.nr * self.vt
self._Vt0 = self.vt0 * (1. + (delta_T * self.avt0) +
(delta_T**2 * self.bvt0))
if (self.tbet):
self._Beta = self.beta * pow(1.01, (delta_T * self.tbet))
else:
self._Beta = self.beta
if self.tme * self.tm != 0.:
self._idsFac = pow((1. + delta_T * self.tm), self.tme)
else:
self._idsFac = 1.
def eval_cqs(self, vPort, getOP=False):
"""
Calculates gate and drain current. Input is a vector as follows:
vPort = [vgs(t), vgd(t), vgs(t-tau), vgd(t-tau)]
getOP has no effect for now
"""
# Calculate junction currents
igs = self.diogs.get_id(vPort[0])
qgs = self.diogs.get_qd(vPort[0])
igd = self.diogd.get_id(vPort[1])
qgd = self.diogd.get_qd(vPort[1])
# Add breakdown current
igs -= self.ib0 * np.exp(-(vPort[0] + self.vbd) / self._k6)
igd -= self.ib0 * np.exp(-(vPort[1] + self.vbd) / self._k6)
DtoSswap = ad.condassign(vPort[0] - vPort[1], 1., -1.)
vds = DtoSswap * (vPort[0] - vPort[1])
vgsi = ad.condassign(DtoSswap, vPort[0], vPort[1])
vgsiT = ad.condassign(DtoSswap, vPort[2], vPort[3])
# Calculate ids.
vx = vgsiT * (1. + self._Beta * (self.vds0 - vds))
ids = (self.a0 + vx * (self.a1 + vx * (self.a2 + vx * self.a3))) \
* np.tanh(self.gama * vds) * self._idsFac
# vgsiT makes more sense than vgsi below? (vgsi in original doc)
ids = ad.condassign((vgsi - self._Vt0), ids, 0.)
# Must ensure ids > 0 for power conservation
ids = ad.condassign(ids, ids, 0.)
# Return numpy array with one element per current source.
iVec = np.array([igs, igd, ids * DtoSswap]) * self.area
qVec = np.array([qgs, qgd]) * self.area
return (iVec, qVec)
# Use AD for eval and deriv function
eval_and_deriv = ad.eval_and_deriv
eval = ad.eval
def power(self, vPort, currV):
"""
Calculate total instantaneous power
Input: control voltages and currents from eval_cqs()
"""
vds = vPort[0] - vPort[1]
# pout = vds*ids + vgs*igs + vgd*igd
pout = vds * currV[2] + vPort[0] * currV[0] + vPort[1] * currV[1]
return pout
def get_OP(self, vPort):
"""
Calculates operating point information
Input: vPort = [vgs , vgd , vgs]
Output: dictionary with OP variables
"""
# First we need the Jacobian
(outV, jac) = self.eval_and_deriv(vPort)
opDict = dict(VGS=vPort[0],
VDS=vPort[0] - vPort[1],
IDS=outV[2],
IGS=outV[0],
IGD=outV[1])
return opDict
def get_noise(self, f):
"""
Return noise spectral density at frequency f
Requires a previous call to get_OP()
Not implemented yet
"""
return None
def __init__(self, instanceName):
IBJT.__init__(self, instanceName)
# Collector-bulk junction
self.cbjtn = Junction()
self.__doc__ += IBJT.__doc__
class BJTi(cir.Element):
"""
Gummel-Poon intrinsic BJT model
This implementation based mainly on previous implementation in
carrot and some equations from Pspice manual.
Terminal order: 0 Collector, 1 Base, 2 Emitter::
C (0) o----, 4----o E (2)
\ /
\ /
---------
|
o
B (1)
Can be used for NPN or PNP transistors.
Intrinsic Internal Topology
+++++++++++++++++++++++++++
Internally may add 2 additional nodes (plus reference) if rb is
not zero: Bi for the internal base node and tib to measure the
internal base current and calculate Rb(ib). The possible
configurations are described here.
1. If RB == 0::
+----------------+--o 0 (C)
| |
/^\ |
( | ) ibc(vbc) |
\|/ |
| /|\
(B) 1 o---------+ ( | ) ice
| \V/
/|\ |
( | ) ibe(vbe) |
\V/ |
| |
+----------------+--o 2 (E)
2. If RB != 0::
+----------------+--o 0 (C)
| |
/^\ |
( | ) ibc(vbc) |
gyr * tib \|/ |
,---, | /|\
(B) 1 o----( --> )----------+ Term : Bi ( | ) ice
`---` | \V/
/|\ |
( | ) ibe(vbe) |
\V/ |
| |
+----------------+--o 2 (E)
gyr v(1,Bi)
,---,
+---( <-- )------+
| `---` |
tref | | voltage: ib/gyr
,---+ |
| | ,---, |
| +---( --> )------+ Term : ib
| `---`
--- gyr ib Rb(ib)
V
Charge sources are connected between internal nodes defined
above. If xcjc is not 1 but RB is zero, xcjc is ignored.
"""
devType = "bjt"
paramDict = dict(
cir.Element.tempItem,
type=('Type (npn or pnp)', '', str, 'npn'),
isat=('Transport saturation current', 'A', float, 1e-16),
bf=('Ideal maximum forward beta', '', float, 100.),
nf=('Forward current emission coefficient', '', float, 1.),
vaf=('Forward early voltage', 'V', float, 0.),
ikf=('Forward-beta high current roll-off knee current', 'A', float,
0.),
ise=('Base-emitter leakage saturation current', 'A', float, 0.),
ne=('Base-emitter leakage emission coefficient', '', float, 1.5),
br=('Ideal maximum reverse beta', '', float, 1.),
nr=('Reverse current emission coefficient', '', float, 1.),
var=('Reverse early voltage', 'V', float, 0.),
ikr=('Corner for reverse-beta high current roll off', 'A', float, 0.),
isc=('Base collector leakage saturation current', 'A', float, 0.),
nc=('Base-collector leakage emission coefficient', '', float, 2.),
rb=('Zero bias base resistance', 'Ohm', float, 0.),
rbm=('Minimum base resistance', 'Ohm', float, 0.),
irb=('Current at which rb falls to half of rbm', 'A', float, 0.),
eg=('Badgap voltage', 'eV', float, 1.11),
cje=('Base emitter zero bias p-n capacitance', 'F', float, 0.),
vje=('Base emitter built in potential', 'V', float, 0.75),
mje=('Base emitter p-n grading factor', '', float, 0.33),
cjc=('Base collector zero bias p-n capacitance', 'F', float, 0.),
vjc=('Base collector built in potential', 'V', float, 0.75),
mjc=('Base collector p-n grading factor', '', float, 0.33),
xcjc=('Fraction of cbc connected internal to rb', '', float, 1.),
fc=('Forward bias depletion capacitor coefficient', '', float, 0.5),
tf=('Ideal forward transit time', 's', float, 0.),
xtf=('Transit time bias dependence coefficient', '', float, 0.),
vtf=('Transit time dependency on vbc', 'V', float, 0.),
itf=('Transit time dependency on ic', 'A', float, 0.),
tr=('Ideal reverse transit time', 's', float, 0.),
xtb=('Forward and reverse beta temperature coefficient', '', float,
0.),
xti=('IS temperature effect exponent', '', float, 3.),
tnom=('Nominal temperature', 'C', float, 27.),
area=('Current multiplier', '', float, 1.))
def __init__(self, instanceName):
cir.Element.__init__(self, instanceName)
# Use junctions to model diodes and capacitors
self.jif = Junction()
self.jir = Junction()
self.jile = Junction()
self.jilc = Junction()
# collector/emitter terminal numbers: may be re-mapped by
# extrinsic device
self._ct = 0
self._et = 2
def process_params(self):
"""
Adjusts internal topology and makes preliminary calculations
according to parameters
"""
# Default configuration assumes rb == 0
# ibe, ibc, ice
self.csOutPorts = [(1, self._et), (1, self._ct), (self._ct, self._et)]
# Controling voltages are vbe, vbc
self.controlPorts = [(1, self._et), (1, self._ct)]
self.vPortGuess = np.array([0., 0.])
# qbe, qbc
self.qsOutPorts = [(1, self._et), (1, self._ct)]
# Define topology first
# Flag to signal if the extra charge Qbx is needed or not
self._qbx = False
self.linearVCCS = []
if self.rb != 0.:
# rb is not zero: add internal terminals
tBi = self.add_internal_term('Bi', 'V')
tib = self.add_internal_term('ib', '{0} A'.format(glVar.gyr))
tref = self.add_reference_term()
# Linear VCCS for gyrator(s)
self.linearVCCS = [((1, tBi), (tib, tref), glVar.gyr),
((tib, tref), (1, tBi), glVar.gyr)]
# ibe, ibc, ice, Rb(ib) * ib
self.csOutPorts = [(tBi, self._et), (tBi, self._ct),
(self._ct, self._et), (tref, tib)]
# Controling voltages are vbie, vbic and gyrator port
self.controlPorts = [(tBi, self._et), (tBi, self._ct), (tib, tref)]
self.vPortGuess = np.array([0., 0., 0.])
# qbie, qbic
self.qsOutPorts = [(tBi, self._et), (tBi, self._ct)]
# Now check if Cjbc must be splitted (since rb != 0)
if (self.cjc != 0.) and (self.xcjc < 1.):
self.qsOutPorts.append((1, self._ct))
self._qbx = True
# In principle we may not need any charge
keepPorts = []
if self.cje + self.tf != 0.:
# keep qbe
keepPorts.append(self.qsOutPorts[0])
if self.cjc + self.tr != 0.:
# keep qbc, qbx (if any)
if self._qbx:
keepPorts += self.qsOutPorts[-2:]
else:
keepPorts.append(self.qsOutPorts[-1])
self.qsOutPorts = keepPorts
# keep track of how many output variables are needed
self.ncurrents = len(self.csOutPorts)
self.ncharges = len(self.qsOutPorts)
# NPN or PNP
if self.type == 'pnp':
self._typef = -1.
else:
self._typef = 1.
# Calculate common variables
# Absolute nominal temperature
self.Tnomabs = self.tnom + const.T0
self.egapn = self.eg - .000702 * (self.Tnomabs**2) \
/ (self.Tnomabs + 1108.)
# jif produces if, cje
self.jif.process_params(self.isat, self.nf, self.fc, self.cje,
self.vje, self.mje, self.xti, self.eg,
self.Tnomabs)
# jir produces ir, cjc
self.jir.process_params(self.isat, self.nr, self.fc, self.cjc,
self.vjc, self.mjc, self.xti, self.eg,
self.Tnomabs)
if self.ise != 0.:
# jile produces ile
self.jile.process_params(self.ise, self.ne, 0, 0, 0, 0, self.xti,
self.eg, self.Tnomabs)
if self.isc != 0.:
# jilc produces ilc
self.jilc.process_params(self.isc, self.nc, 0, 0, 0, 0, self.xti,
self.eg, self.Tnomabs)
# Constants needed for rb(ib) calculation
if self.irb != 0.:
self._ck1 = 144. / self.irb / self.area / np.pi / np.pi
self._ck2 = np.pi * np.pi * np.sqrt(self.irb * self.area) / 24.
def set_temp_vars(self, temp):
"""
Calculate temperature-dependent variables, given temp in deg. C
"""
# Absolute temperature (note self.temp is in deg. C)
self.Tabs = const.T0 + temp
# Normalized temp
self.tnratio = self.Tabs / self.Tnomabs
tnXTB = pow(self.tnratio, self.xtb)
# Thermal voltage
self.vt = const.k * self.Tabs / const.q
# Temperature-adjusted egap
self.egap_t = self.eg - .000702 * (self.Tabs**2) / (self.Tabs + 1108.)
# set temperature in juctions
self.jif.set_temp_vars(self.Tabs, self.Tnomabs, self.vt, self.egapn,
self.egap_t)
self.jir.set_temp_vars(self.Tabs, self.Tnomabs, self.vt, self.egapn,
self.egap_t)
# Adjust ise and isc (which have different temperature variation)
if self.ise != 0.:
self.jile.set_temp_vars(self.Tabs, self.Tnomabs, self.vt,
self.egapn, self.egap_t)
self.jile._t_is /= tnXTB
if self.isc != 0.:
self.jilc.set_temp_vars(self.Tabs, self.Tnomabs, self.vt,
self.egapn, self.egap_t)
self.jilc._t_is /= tnXTB
# Now some BJT-only variables
self._bf_t = self.bf * tnXTB
self._br_t = self.br * tnXTB
def eval_cqs(self, vPort):
"""
Calculates currents/charges
Input is a vector may be one of the following, depending on
parameter values::
vPort = [vbe, vbc]
vPort = [vbie, vbic, v1_i] (gyrator voltage, rb != 0)
Output also depends on parameter values. Charges only present
if parameters make them different than 0 (i.e., cje, tf, cjc,
etc. are set to nonzero values)::
iVec = [ibe, ibc, ice]
iVec = [ibe, ibc, ice, gyr*ib*Rb] (rb != 0)
qVec = [qbe, qbc]
qVec = [qbe, qbc, qbx] (rb != 0 and cjc != 1)
"""
# Invert control voltages if needed
vPort1 = self._typef * vPort
# Calculate regular PN junctions currents and charges
ibf = self.jif.get_id(vPort1[0])
ibr = self.jif.get_id(vPort1[1])
if self.ise != 0.:
ile = self.jile.get_id(vPort1[0])
else:
ile = 0.
if self.isc != 0.:
ilc = self.jilc.get_id(vPort1[1])
else:
ilc = 0.
# Kqb
q1m1 = 1.
if self.var != 0.:
q1m1 -= vPort1[0] / self.var
if self.vaf != 0.:
q1m1 -= vPort1[1] / self.vaf
kqb = 1. / q1m1
# We need extra checking to consider the following
# possibilities to create the AD tape:
#
# 1. both ikf and ikr are zero -> no tape generated
# 2. One of them is nonzero but both ibf and ibr are zero -> want tape
# but only for the nonzero parameter
if self.ikf + self.ikr != 0.:
q2 = 0.
if self.ikf != 0.:
q2 += ibf / self.ikf
if self.ikr != 0.:
q2 += ibr / self.ikr
kqb *= .5 * (1. + np.sqrt(1. + 4. * q2))
# Create output vector [ibe, ibc, ice, ...]
iVec = np.zeros(self.ncurrents, dtype=type(ibf))
qVec = np.zeros(self.ncharges, dtype=type(ibf))
# ibe
iVec[0] = ibf / self._bf_t + ile
# ibc
iVec[1] = ibr / self._br_t + ilc
# ice
iVec[2] = (ibf - ibr) / kqb
# RB
if self.rb != 0.:
# Using gyrator
# vPort1[2] not defined if rb == 0
# ib has area effect included (removed by _ck1 and _ck2)
ib = vPort1[2] * glVar.gyr
if self.irb != 0.:
ib1 = np.abs(ib)
x = np.sqrt(1. + self._ck1 * ib1) - 1.
x *= self._ck2 / np.sqrt(ib1)
tx = np.tan(x)
c = self.rbm + 3. * (self.rb - self.rbm) \
* (tx - x) / (x * tx * tx)
rb = ad.condassign(ib1, c, self.rb)
else:
rb = self.rbm + (self.rb - self.rbm) / kqb
# Output is gyr * ib * rb. It is divided by area^2 to
# compensate that the whole vector is multiplied by area
# at the end
iVec[3] = glVar.gyr * ib * rb / pow(self.area, 2)
vbcx = ib * rb / self.area + vPort1[1]
# Charges -----------------------------------------------
# Note that if tf == 0 and cje == 0, nothing is calculated and
# nothing is assigned to the output vector.
# qbe is the first charge (0)
if self.tf != 0.:
# Effective tf
tfeff = self.tf
if self.vtf != 0.:
x = ibf / (ibf + self.itf)
tfeff *= (1. + self.xtf * x * x *
ad.safe_exp(vPort1[1] / 1.44 / self.vtf))
qVec[0] = tfeff * ibf
if self.cje != 0.:
qVec[0] += self.jif.get_qd(vPort1[0])
# qbc
if self._qbx:
if self.tr != 0.:
qVec[-2] = self.tr * ibr
if self.cjc != 0.:
qVec[-2] += self.jir.get_qd(vPort1[1]) * self.xcjc
# qbx
qVec[-1] = self.jir.get_qd(vbcx) * (1. - self.xcjc)
else:
if self.tr != 0.:
qVec[-1] = self.tr * ibr
if self.cjc != 0.:
qVec[-1] += self.jir.get_qd(vPort1[1])
# Consider area effect and invert currents if needed
iVec *= self.area * self._typef
qVec *= self.area * self._typef
return (iVec, qVec)
def power(self, vPort, currV):
"""
Calculate total instantaneous power
Input: control voltages as in eval_cqs() and currents returned
by eval_cqs()
"""
vce = vPort[0] - vPort[1]
if self.rb != 0.:
# currV[3] = ib * Rb * gyr
# vPort[2] = ib / gyr
pRb = currV[3] * vPort[2]
else:
pRb = 0.
# pout = ibe * vbie + ibc * vbic + vce * ice + pRb
pout = currV[0] * vPort[0] + currV[1] * vPort[1] \
+ currV[2] * vce + pRb
return pout
def get_OP(self, vPort):
"""
Calculates operating point information
Input: same as eval_cqs
Output: dictionary with OP variables
For now it is quite incomplete
"""
# First we need the Jacobian
(outV, jac) = self.eval_and_deriv(vPort)
power = self.power(vPort, outV)
opDict = dict(
VBE=vPort[0],
VCE=vPort[0] - vPort[1],
IB=outV[0] + outV[1],
IC=outV[2] - outV[1],
IE=-outV[2] - outV[0],
Temp=self.temp,
Power=power,
gm=jac[2, 0] - jac[1, 0],
rpi=1. / (jac[0, 0] + jac[1, 0]),
)
return opDict
def get_noise(self, f):
"""
Return noise spectral density at frequency f
Requires a previous call to get_OP()
Not implemented yet
"""
return None
class BJT(IBJT):
"""
Bipolar Junction Transistor
---------------------------
This device accepts 3 or 4 terminal connections.
Netlist examples::
bjt:q1 2 3 4 1 model = mypnp isat=4e-17 bf=147 iss=10fA
bjt:q2 2 3 4 model = mypnp isat=4e-17 bf=147 vaf=80 ikf=4m
svbjt:q3 2 3 4 1 model = mypnp vaf=80 ikf=4m iss=15fA
# Electro-thermal versions
bjt_t:q2 2 3 5 1 pout gnd model = mypnp
svbjt_t:q3 2 3 5 1 pout gnd model = mypnp
# Model statement
.model mypnp bjt_t (type=pnp isat=5e-17 cje=60fF vje=0.83 mje=0.35)
Extrinsic Internal Topology
+++++++++++++++++++++++++++
RC, RE and a Collector-Bulk connection are added to intrinsic
BJT models::
RC Term: ct Term: et RE
C (0) o---/\/\/\/--+-----, 4----/\/\/\/----o E (2)
| \ /
| \ /
----- ---------
/ \ |
/ \ o
-----
| B (1)
o Bulk (3)
If RE or RC are zero the internal nodes (ct, et) are not
created. If only 3 connections are specified then the
Bulk-Collector junction is not connected.
Important Note
++++++++++++++
This implementation does not account for the power dissipation
in RE, RC. Use external thermal resistors if that is needed.
Intrinsic Model Information
+++++++++++++++++++++++++++
"""
# Additional documentation
extraDoc = IBJT.__doc__
# Create electrothermal device
makeAutoThermal = True
isNonlinear = True
# Device category
category = "Semiconductor devices"
# devtype is the 'model' name: remove the 'i' from intrinsic name
devType = IBJT.devType
# Do not set numTerms to allow 3 or 4 terminals to be connected
paramDict = dict(
IBJT.paramDict.items(),
re=('Emitter ohmic resistance', 'Ohm', float, None),
rc=('Collector ohmic resistance', 'Ohm', float, None),
cjs=('Collector substrate capacitance', 'F', float, 0.),
mjs=('substrate junction exponential factor', '', float, 0.),
vjs=('substrate junction built in potential', 'V', float, 0.75),
ns=('substrate p-n coefficient', '', float, 1.),
iss=('Substrate saturation current', 'A', float, 1e-14))
def __init__(self, instanceName):
IBJT.__init__(self, instanceName)
# Collector-bulk junction
self.cbjtn = Junction()
self.__doc__ += IBJT.__doc__
def process_params(self, thermal=False):
# Remove tape if present
ad.delete_tape(self)
if thermal:
extraTerms = 2
else:
extraTerms = 0
# First check external connections
if self.numTerms == 3 + extraTerms:
self.__addCBjtn = False
elif self.numTerms == 4 + extraTerms:
self.__addCBjtn = True
else:
raise cir.CircuitError('{0}: Wrong number of connections. \
Can only be {1} or {2}, {3} found.'.format(self.instanceName, 3 + extraTerms,
4 + extraTerms, self.numTerms))
# Remove internal terminals
self.clean_internal_terms()
# Tell autothermal to re-generate thermal ports
self.__addThermalPorts = True
extraVCCS = list()
if self.re != None:
# Add et node and translate port descriptions
self._et = self.add_internal_term('et', 'V')
extraVCCS += [((2, self._et), (2, self._et),
self.area / self.re)]
if self.rc != None:
# Add ct node and translate port descriptions
self._ct = self.add_internal_term('ct', 'V')
extraVCCS += [((0, self._ct), (0, self._ct),
self.area / self.rc)]
# Process parameters from intrinsic device: emitter and
# collector terminals are already substituted.
IBJT.process_params(self)
# Calculate variables in junction
self.cbjtn.process_params(self.iss, self.ns, self.fc, self.cjs,
self.vjs, self.mjs, self.xti, self.eg,
self.Tnomabs)
# Add RE, RC resistors (if any)
self.linearVCCS += extraVCCS
if self.__addCBjtn:
# Add bulk-collector junction
self.__bccn = len(self.controlPorts)
self.__bcon = len(self.csOutPorts)
self.controlPorts.append((3, self._ct))
self.csOutPorts.append((3, self._ct))
if self.cjs != 0.:
self.qsOutPorts.append((3, self._ct))
# Initial guess for input ports:
try:
if len(self.vPortGuess) < len(self.controlPorts):
self.vPortGuess = np.concatenate(
(self.vPortGuess, [1]), axis=0)
except AttributeError:
# Ignore if vPortGuess not provided
pass
# Adjust temperature
self.set_temp_vars(self.temp)
def set_temp_vars(self, temp):
"""
Calculate temperature-dependent variables, given temp in deg. C
"""
# Remove tape if present
ad.delete_tape(self)
# First calculate variables from base class
IBJT.set_temp_vars(self, temp)
# Adjust collector-bulk junction temperature
self.cbjtn.set_temp_vars(self.Tabs, self.Tnomabs, self.vt,
self.egapn, self.egap_t)
def eval_cqs(self, vPort, getOP=False):
"""
vPort is a vector with control voltages
"""
if self.__addCBjtn:
# calculate currents and charges in base class
(iVec1, qVec1) = IBJT.eval_cqs(self, vPort)
# Add contribution of substrate. Ignore extra control
# ports only used for power calculation
v1 = vPort[self.__bccn] * self._typef
isub = self.cbjtn.get_id(v1) * self.area * self._typef
iVec = np.concatenate((iVec1, [isub]), axis=0)
if self.cjs != 0.:
qsub = self.cbjtn.get_qd(v1) * self.area * self._typef
qVec = np.concatenate((qVec1, [qsub]), axis=0)
else:
qVec = qVec1
return (iVec, qVec)
else:
return IBJT.eval_cqs(self, vPort)
# Create these using the AD facility
eval_and_deriv = ad.eval_and_deriv
eval = ad.eval
def power(self, vPort, currV):
"""
Calculate total instantaneous power
Power in RE, RC not considered.
Input: control voltages as in eval_cqs() and currents
returned by eval_cqs()
"""
pout = IBJT.power(self, vPort, currV)
if self.__addCBjtn:
# add power from substrate junction (RE, RC not counted)
pout += vPort[self.__bccn] * currV[self.__bcon]
return pout
