def get_db(spec_file, intent, interp_method='spline', sim_env='TT'): # initialize transistor database from simulation data mos_db = MOSDBDiscrete([spec_file], interp_method=interp_method) # set process corners mos_db.env_list = [sim_env] # set layout parameters mos_db.set_dsn_params(intent=intent) return mos_db
def design(amp_dsn_specs, amp_char_specs_fname, amp_char_specs_out_fname): nch_config = amp_dsn_specs['nch_config'] pch_config = amp_dsn_specs['pch_config'] print('create transistor database') nch_db = MOSDBDiscrete([nch_config]) pch_db = MOSDBDiscrete([pch_config]) nch_db.set_dsn_params(**amp_dsn_specs['nch']) pch_db.set_dsn_params(**amp_dsn_specs['pch']) result = design_amp(amp_dsn_specs, nch_db, pch_db) if result is None: raise ValueError('No solution.') pprint.pprint(result) # update characterization spec file amp_char_specs = read_yaml(amp_char_specs_fname) # update bias var_dict = amp_char_specs['measurements'][0]['testbenches']['ac'][ 'sim_vars'] for key in ('vtail', 'vindc', 'voutdc'): var_dict[key] = result[key] for key in ('vdd', 'cload'): var_dict[key] = amp_dsn_specs[key] # update segments seg_dict = amp_char_specs['layout_params']['seg_dict'] for key in ('in', 'load', 'tail'): seg_dict[key] = result['seg_' + key] with open_file(amp_char_specs_out_fname, 'w') as f: yaml.dump(amp_char_specs, f) return result
def get_db(nch_dir, pch_dir, intent='standard', interp_method='spline', sim_env='tt'): env_list = [sim_env] nch_db = MOSDBDiscrete([nch_dir], interp_method=interp_method) pch_db = MOSDBDiscrete([pch_dir], interp_method=interp_method) nch_db.env_list = pch_db.env_list = env_list nch_db.set_dsn_params(intent=intent) pch_db.set_dsn_params(intent=intent) return nch_db, pch_db
def get_mos_db(spec_file, intent, lch=None, interp_method='spline', sim_env='tt') -> MOSDBDiscrete: # Initialize transistor database from simulation data mos_db = MOSDBDiscrete([spec_file], interp_method=interp_method) # Set process corners mos_db.env_list = [sim_env] # Set layout parameters mos_db.set_dsn_params(intent=intent) if lch != None: mos_db.set_dsn_params(lch=lch) return mos_db
def query(vgs=None, vds=None, vbs=0.0, vstar=None, env_list=None): """Get interpolation function and plot/query.""" spec_list = [spec_file] if env_list is None: env_list = [env_default] # initialize transistor database from simulation data nch_db = MOSDBDiscrete(spec_list, interp_method=interp_method) # set process corners nch_db.env_list = env_list # set layout parameters nch_db.set_dsn_params(intent=intent) # returns a dictionary of smal-signal parameters return nch_db.query(vbs=vbs, vds=vds, vgs=vgs, vstar=vstar)
def estimate_vth(db: MOSDBDiscrete, vgs: float, vbs: float, is_nch: bool, lch: float) -> float: """Estimates the threshold voltage of a device. TODO: Currently assumes a quadratic model for vgs/lch < 1V/um, otherwise assumes a linear model. Inputs: db: MOSDBDiscrete associated with the device. is_nch: Boolean. True for NMOS, false otherwise. vgs: Gate-source voltage of the device. vbs: Bulk/body-source voltage of the device. lch: Channel length. Returns: vth: Threshold voltage in volts. Note that this can be negative. """ op = db.query(vgs=vgs, vds=vgs, vbs=vbs) vds_ref = vgs if is_nch else -vgs vov = op['vstar'] if vds_ref / lch < 1e6 else op['vstar'] / 2 if is_nch: return vgs - vov else: return vgs + vov
def plot_data(name='ibias', bounds=None, unit_val=None, unit_label=None): """Get interpolation function and plot/query.""" env_list = [env_default] vbs = 0.0 nvds = 41 nvgs = 81 spec_list = [spec_file] print('create transistor database') nch_db = MOSDBDiscrete(spec_list, interp_method=interp_method) nch_db.env_list = env_list nch_db.set_dsn_params(intent=intent) f = nch_db.get_function(name) vds_min, vds_max = f.get_input_range(1) vgs_min, vgs_max = f.get_input_range(2) if bounds is not None: if 'vgs' in bounds: v0, v1 = bounds['vgs'] if v0 is not None: vgs_min = max(vgs_min, v0) if v1 is not None: vgs_max = min(vgs_max, v1) if 'vds' in bounds: v0, v1 = bounds['vds'] if v0 is not None: vds_min = max(vds_min, v0) if v1 is not None: vds_max = min(vds_max, v1) # query values. vds_test = (vds_min + vds_max) / 2 vgs_test = (vgs_min + vgs_max) / 2 pprint.pprint(nch_db.query(vbs=vbs, vds=vds_test, vgs=vgs_test)) vbs_vec = [vbs] vds_vec = np.linspace(vds_min, vds_max, nvds, endpoint=True) vgs_vec = np.linspace(vgs_min, vgs_max, nvgs, endpoint=True) vbs_mat, vds_mat, vgs_mat = np.meshgrid(vbs_vec, vds_vec, vgs_vec, indexing='ij', copy=False) arg = np.stack((vbs_mat, vds_mat, vgs_mat), axis=-1) ans = f(arg) vds_mat = vds_mat.reshape((nvds, nvgs)) vgs_mat = vgs_mat.reshape((nvds, nvgs)) ans = ans.reshape((nvds, nvgs, len(env_list))) formatter = ticker.ScalarFormatter(useMathText=True) formatter.set_scientific(True) formatter.set_powerlimits((-2, 3)) if unit_label is not None: zlabel = '%s (%s)' % (name, unit_label) else: zlabel = name for idx, env in enumerate(env_list): fig = plt.figure(idx + 1) ax = fig.add_subplot(111, projection='3d') cur_val = ans[..., idx] if unit_val is not None: cur_val = cur_val / unit_val ax.plot_surface(vds_mat, vgs_mat, cur_val, rstride=1, cstride=1, linewidth=0, cmap=cm.cubehelix) ax.set_title('%s (corner=%s)' % (name, env)) ax.set_xlabel('Vds (V)') ax.set_ylabel('Vgs (V)') ax.set_zlabel(zlabel) ax.w_zaxis.set_major_formatter(formatter) plt.show()