Bipolar Junction Transistor (SPICE Gummel Poon)

Netlist Entry

Qxxxx collector base emitter [substrate] modelname [area] [OFF] [IC=vbe,vce]
[TEMP=local_temp] [M=mult] [DTEMP=dtemp]

NPN BJT Model Syntax

.model modelname NPN ( parameters )

PNP BJT Model Syntax

.model modelname PNP ( parameters )

Lateral PNP BJT Model Syntax

.model modelname LPNP ( parameters )

BJT Model Parameters

The symbols '???MATH???\times???MATH???' and '???MATH???\div???MATH???' in the Area column means that the specified parameter should be multiplied or divided by the area factor respectively.

Hspice Temperature Parameters

The parameters defined in the following table are temperature coefficients and apply if the Hspice temperature model is enabled. This is the case if one or more of the following parameters are defined in the .MODEL statement:

TLEV, TLEVC, TIKF1, TIKF2, TIKR1, TIKR2, TIRB1, TIRB2.

If none of these parameters are specified, the standard (SPICE) temperature model is enabled and the following parameters have no effect.

Notes

The bipolar junction transistor model in SPICE is an adaptation of the integral charge control model of Gummel and Poon.

This modified Gummel-Poon model extends the original model to include several effects at high bias levels. The model will automatically simplify to the simpler Ebers-Moll model when certain parameters are not specified.

The dc model is defined by the parameters IS, BF, NF, ISE, IKF, and NE which determine the forward current gain characteristics, IS, BR, NR, ISC, IKR, and NC which determine the reverse current gain characteristics, and VAF and VAR which determine the output conductance for forward and reverse regions. Three ohmic resistances RB, RC, and RE are included, where RB can be high current dependent. Base charge storage is modelled by forward and reverse transit times, TF and TR, the forward transit time TF being bias dependent if desired, and non-linear depletion layer capacitances which are determined by CJE, VJE, and MJE for the B-E junction, CJC, VJC, and MJC for the B-C junction and CJS, VJS, and MJS for the C-S (Collector-Substrate) junction. The temperature dependence of the saturation current, IS, is determined by the energy-gap, EG, and the saturation current temperature exponent, XTI. Additionally base current temperature dependence is modelled by the beta temperature exponent XTB in the new model.

This implementation includes further enhancements to model quasi-saturation effects. This is governed by the model parameters RCO, QCO, GAMMA and for temperature dependence, QUASIMOD, VG, D and CN. The quasi-saturation model is compatible with PSpice. Hspice models may be accommodated by setting RC to zero and RCO to the value of RC in the Hspice model.

References

The Quasi-saturation model was developed from the following paper:

George M. Kull, Laurence W. Nagel, Shiuh-Wuu Lee, Peter Lloyd, E. James Prendergast and Heinz Dirks, "A Unified Circuit Model for Bipolar Transistors Including Quasi-Saturation Effects". IEEE Transactions on Electron Devices, Vol. ED-32, No 6 June 1985, pages 1103-1113