关于晶体管VBIC模型的问题？

JYOO

I am a beginner of ic design.I have a problem about the VBIC model of BJT.As everybody know,the ordinary BJT modle only have 3 nodes named E,B,C.But the VBIC model have 4 nodes named E,B,C,S.I know this node S means substrate by reading the VBIC model note.Should I connect S to the GND directly in circuit design and simulation or the other way? THANKS FOR YOUR HELP! :em04:

icsoul

你在哪看到的这个模型？看看模型文档。

jyoo

在附件里面是图
Using the VBIC Bipolar Transistor Model
The VBIC (Vertical Bipolar Inter-Company) model is a new bipolar transistor model for Star-Hspice. You can use VBIC by specifying parameter LEVEL=4 for the bipolar transistor model.
VBIC addresses many problems of the SPICE Gummel-Poon model:
More accurate modeling of Early effect
Parasitic substrate transistor
Modulation of collector resistance
Avalanche multiplication in collector junction, parasitic capacitances of base-emitter overlap in double poly BJTs, and self heating.
Understanding the History of VBIC
VBIC was developed by engineers at several companies. The detailed equations1 for all elements are given in the referenced publication. Recent information and source code can be found on the web site:
http://www-sm.rz.fht-esslingen.de/institute/iafgp/neu/VBIC/index.html
Our implementation is compliant to standard VBIC. Self-heating and excess phases have been implemented or enabled in this version 99.4
The large signal equivalent circuit for VBIC is shown in Transient Analysis. Capacitors CBCO, CBEO and resistors RCX, RBX, RE, and RS are linear elements, all other elements of the equivalent circuit are nonlinear.

icsoul

substrate接地与否与模型没有关系吧？
P substrate 应该接GND，若是n substrate应该接VDD。

jyoo

我问过一个人，他说还不一定是接地！有可能接一个电压！把我都弄晕了！因为我用的模型库里面由这个S引脚，所以很担心我的接法不对对电路仿真造成影响

icsoul

这我就不清楚了，你两种都仿真验证一下性能就知道了。

icb

理论上来说 两种豆可以

forman1115

严格来说如果 是P SUB的话应该接到最低电压，N SUB的话接到最高电压，目的是使PN结保持零偏或者反偏

zzhangqilinn

仿真时不能直接接地的，bjt可以使用四端仿真

hahabobo1

thank you