• State Resolved
  • Locked Locked
  • Replies 2 replies
  • Subscribers 47 subscribers
  • Views 154 views
  • Users 0 members are here
Support feedback
Options
Options
Similar topics

This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

LM358B: Characteristics of the LM358B SPICE model

Hiroki Hagihara
Prodigy 20 points
Part Number: LM358B
Other Parts Discussed in Thread: LM2904B,

Tool/software:

I have simulated open-loop gains using the SPICE model of the LM358B. (lmx58b_lm2904b.lib)

The open-loop gain in the simulation result (59.9V/mV) is smaller than the minimum value (70V/mV) in the datasheet. Does this mean that the gain in the SPICE model is smaller than the gain in the actual part?
Doesn't that mean the model is wrong?

Thank you in advance for your reply.

  • 0
    TI__Mastermind 29086 points

    Hello Hiroki-san,

    The way to measure AOL in the DC sweep domain is by changing the output voltage without changing the input common-mode or supply voltage. The way to measure AOL in the AC domain (only in SPICE) is by opening the feedback loop with large inductors and capacitors. One of the ways to do this is shown below.

    The open loop gain is 97.45dB, which is 74.5V/mV, which is greater than the minimum voltage gain of this device.

    Best,
    Jerry

  • 0 in reply to Gerasimos Madalvanos
    Prodigy 20 points

    Thank you for an answer.

    The evaluation method is different between actual measurement and SPICE.
    Is it correct that the SPICE model was created to be consistent with the datasheet in the way SPICE evaluates it?