hsipce 不收敛的解决

yxlk

解决spice在tran时的internal timestep too small问题的方法
Transient Analysis: 也就是一般的暂态分析.一般错误的
Message 为:-"Internal timestep too small."
另外,也会常看到 "Singular Matrix", or "Gmin/Source Stepping
Failed" 这样的 Error Message.解决这个问题没有一定的方法,根
据我们的经验,我们大致把它们说明如後:
# i# \" w: f, K1. 电路错误:指的是由使用者本身电路,有不正常的接线或短路等,例如将电源
, }: P- J! Z& g# D) M! [接到输出端,而造成SPICE在运算的时候无法收敛.根据Ref[38] 的建议,请
. M+ b# S2 w- G( q' X你确认以下之状况:
4 ]) g( o6 s% J0 F) O: `! d3 ?Make sure that all of the circuit connections are valid. Check for
8 v: e8 J, @& z" i3 V/ o5 i0 Q3 G) ~' Xincorrect node numbering or dangling nodes. Also, verify component
2 R" ~3 A0 V+ P; vpolarity.
) X) b3 ~5 C3 M4 k9 nMake sure you didn't use the letter O instead of a zero (0).
Check for syntax mistakes. Make sure that you used the correct SPICE
units (i.e. MEG instead of M(milli) for 1E6).
Make sure that there's a DC path from every node to ground.
% h( g1 l- n9 G5 p& d- V( w& H1 [  xMake sure that there are at least two connections at every node.
- L+ c7 S- |6 S# X# O$ kMake sure that there are no loops of inductors or voltage sources.
: }6 s4 o9 G1 LMake sure that there are no series capacitors or current sources.
Place the ground (node 0) somewhere in the circuit. Be careful when
! [; y; ^+ ^0 N* V4 l! y8 Q  a6 Pyou use floating grounds; you may need to connect a large resistor from
/ b8 S1 S( Q! z# ^  Athe floating node to ground.
Make sure that voltage/current generators use realistic values, and
verify that the syntax is correct.
( L: y; Q9 v  r# l9-46 VLSI 设计概论 / 实习
Make sure that dependent source gains are correct, and that B element
expressions are reasonable. If you are using division in an expression,
3 B; S# W  V# d" }verify that division by zero cannot occur.
Make sure that there are no unrealistic model parameters; especially if
you have manually entered the model into the netlist.
Make sure that all resistors have a value. In SPICE 3, resistors without
# j6 O4 K* q: A  |; ovalues are given a default value of 1k Ohm.
: r: N$ G7 E! L$ v$ z" gNegative capacitor and inductor values are allowed in SPICE 3. They
5 {( \7 g  m0 [$ Y% I. a% B/ pwill not be flagged as an error, but can cause timestep problems,
+ K2 `  H% X: p4 Edepending on the topology of the circuit.
2. 检查Feedback : 所指的是在序向逻辑电路中所产生的,你可以检查一下你的
1 x% W) S7 l1 q! j, G0 ^- s3 I; p电路的FeedBack Path的Delay,在不影响电路功能的情形下,是否可以调快一
点或慢一点.
# _- O, E, Z! V  h4 W: y7 z

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wu68aq

谢谢分享

lxuande

好好学习，天天向上。