:roll: Anybody?
Looking for LM394 spice model
- Thread starter Moby
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> LM394 spice model
Bob hates SPICE, so National only has SPICE models for the devices they adopted from other vendors like ComLinear.
What do you need to know that can't be adequately modeled by 2N2222 or 2N2906 type generic small NPN models? One "flaw" in SPICE is that any two transistors (same type and bias) match EXACTLY, so a super-match LM194 may not look any different than a generic transistor. LM194 has lower base resistance, but most SPICE models have improbably low base resistances (10Ω???). Most generic small NPN models give optimistic Beta values, not as high as an actual 194 but in that range. If you are relying on the 194's very high Beta, you can guestimate the conditions with pencil and paper. If you are relying on the 194's very high Beta, you may be in for trouble unless you account for variation of Beta and keep a very clean board.
Personally, I SPICE with 2N2222. If that isn't good enough, then I need a better plan, not a magic transistor. Then when I build it, I know that some 2N2222 will be more leaky and noisy than SPICE models say, so in critical stages I'll use a better device (or just try 2N2222/3906/etc: very often they work close-enough to theory).
Bob hates SPICE, so National only has SPICE models for the devices they adopted from other vendors like ComLinear.
What do you need to know that can't be adequately modeled by 2N2222 or 2N2906 type generic small NPN models? One "flaw" in SPICE is that any two transistors (same type and bias) match EXACTLY, so a super-match LM194 may not look any different than a generic transistor. LM194 has lower base resistance, but most SPICE models have improbably low base resistances (10Ω???). Most generic small NPN models give optimistic Beta values, not as high as an actual 194 but in that range. If you are relying on the 194's very high Beta, you can guestimate the conditions with pencil and paper. If you are relying on the 194's very high Beta, you may be in for trouble unless you account for variation of Beta and keep a very clean board.
Personally, I SPICE with 2N2222. If that isn't good enough, then I need a better plan, not a magic transistor. Then when I build it, I know that some 2N2222 will be more leaky and noisy than SPICE models say, so in critical stages I'll use a better device (or just try 2N2222/3906/etc: very often they work close-enough to theory).
Thanks PRR, i did the same, jus wonder is there any theoretical change :?: I tried with mat 02 and ssm, and notice some small difference. :green:
tk@halmi
Well-known member
The SSM2210 you have tried is very close to the LM394.
Once you have the required, DC bias, bandwidth and transient response move on to prototyping as soon as possible. Otherwise you will spend months inside the "SPICE CAVE" and people will not recognize you when you come out. The real circuit will behave different almost without exception.
Once you have the required, DC bias, bandwidth and transient response move on to prototyping as soon as possible. Otherwise you will spend months inside the "SPICE CAVE" and people will not recognize you when you come out. The real circuit will behave different almost without exception.
Thanks :wink:
