VBIC Model History Notes

Release 1.2, Sep 18, 1999

1.2 updates:	Sep 24, 1999
	3-terminal version defined
	base-emitter breakdown model added
	reach-through model added for B-C depletion capacitance
	homotopy version of code added
	limited exponential version added
	Completely new code generation added
	C, FORTRAN, Verilog-A, Perl, and MAST code provided
	Bug in psibi mapping with temperature fixed
	Bugs in electrothermal derivatives and solver stamp fixed
	DTEMP local temperature difference parameter added
	VERS and VREV (version revision) parameters added
	NKF high current beta rolloff parameter added
	Temperature dependence added to IKF
	Ability to select SGP qb formulation added (QBM)
	Ability to separate IS for fwd and rev added (ISRR)
	Fixed collector-substrate capacitance added (CCSO)
	Separate temperature coeffs added for RCX, RBX, RBP
	tl node eliminated
	 > Ith  flows from dt to ground and so is negative
	 > Ixzf flows from xf1 to ground as so is negative of Itzf
	Igc component moved into Ibc
	Icc broken into forward and reverse components, Itxf or Itzf and Itzr

1.1.5 updates:	Jul 28, 1996
	Dependence of Irbp on Vbci added to "branch currents"
	Itf/Itr renamed Itfi/Itri to avoid name conflicts
	Resistor collapse and code bypass condition
		changed from par==0 to par<=0
	Branch current and charge dependencies separated
		for self-heating and no self-heating
	Depletion charge and avalanche routines that provide
		derivatives for self-heating added
	Self-heating solver and examples added (HBT)
	Extra external node added for self-heating to allow
		coupling of thermal models between devices

1.1.4 updates:	Qbe diffusion term made equivalent to SGP (divide by qb)
	Solver example including excess phase added
		(Icc separated into Itzf|Itxf and Itzr for this)
	Error in sgp_to_vbic in PTF to TD translation fixed

1.1.3 updates:	Ith bug fixed and Igc term added
	BFN exponent added to 1/f noise
	RTH default changed to zero
	parameter aliases added

1.1.2 updates:	EAI bug fixed in PE/PC/PStemperature mapping
	single->double precision in decomp/solve/vbict/QCDEPL
	scale changed to vscale in solver to avoid name conflict
	avalanche model added, element Igc
	initialization changed in solver
	AC solver and AC and temperature tests added
	missing term in derf_Vrci added
	potential numerical problem in Irci fixed

1.1.1 updates:	VJ->V bug fixed in qj definition
	potential numerical problems with ITF fixed
	typo derf_Vcci fixed to derf_Vrci in FORTRAN code