SIMPLORER User Manual V6.0 - FER-a

4.6 SPICE-Compatible Models
• Diodes
• Bipolar Junction Transistors
• Field-Effect Transistors
• Line Models
4.6.1 Introduction
SIMPLORER 6.0 — Manual 151
SPICE-compatible models in SIMPLORER include all diode and transistor models provided in
Berkeley SPICE 3f5, the lossy line model (LTRA), and the newest process-based MOSFET
models (BSIM and EKV). A four-pin version of the BJT model is provided. The SPICE semiconductor
capacitor and resistor models are not included. The models support both AC and DC
analysis. SPICE-compatible models appear in the Circuit folder of the «Basics» tab.
Model Implementation
SPICE-compatible models are basic components at the device level. They run code from Berkeley
SPICE 3f5, with additions for the BSIM3, BSIM4, and EKV model. The library interface
to SIMPLORER mimics the SPICE circuit environment.
The device models in PSPICE, derived from an earlier version 2g6 of Berkeley SPICE, have
evolved independently and they are comparable to those in SPICE 3f5, but they are not necessarily
identical. A reference on these differences is Semiconductor Device Modeling with
SPICE, 2nd ed., by Guiseppe Massobrio and Paulo Antognetti, McGraw-Hill, 1993. This book
also describes the differences with HSPICE models.
Vendor-specific SPICE models are often implemented as a SPICE subcircuit composed of several
basic components. The SPICE converter in SIMPLORER can handle the conversion of
both basic component models, and subcircuit models.
A small number of model parameter names were changed to conform to SIMPLORER naming
conventions. SPICE can sometimes accept two versions of a parameter name (for example
VTO or VT0). SIMPLORER models accept only the preferred name (VTO). For transistor models,
SPICE accepts a vector of initial voltages (for example IC with 3 elements), SIMPLORER
models accept the alternative separate parameters for initial voltages (for example ICVDS,
ICVGS, and ICVBS).
SPICE-compatible SIMPLORER models combine model and instance parameters in one component,
whereas SPICE manages these parameter sets separately. SPICE also handles default
parameters differently. See also “Default Parameter Handling” on page 151.
SPICE-compatible SIMPLORER models perform their own integration of charges and other
state variables, always using the 2nd-order trapezoidal integration method. They also perform
their own estimates of local truncation error, for use in limiting the time step. For these and
other reasons, the SPICE-compatible models can behave differently than typical SIMPLORER
models. See also “Initial Conditions” on page 152 and “Convergence Tolerances” on page 153.
Default Parameter Handling
For SPICE-compatible models, the default values were determined by creating a new instance
of the device, and querying the library code for parameter values at the default temperature