LM193-MIL: LM193 28V Pspice model

Nicholas Navarrete

Part Number: LM193-MIL
Other Parts Discussed in Thread: LM339

Tool/software:

Hello,

I am looking into the response of the device operating at different frequencies.

It is being used with 28V on the voltage supply pin, I know that the P-spice model you guys provide is when the device is operating at 5.1V . I was wondering if you had a model for the 28V case or any modifications to the 5.1V P-spice file that would make the op amp perform more closely to the 28V case.

Thank you

7 months ago

0 Paul Grohe 7 months ago

TI__Guru 54976 points

Hello Nicholas,

Sorry, we do not have a 28V model. All I can find is the 5V model.

Some of these older (20+ years) models do have higher voltage models, and would have a .30_1 extension - but this one does not since the datasheet table specs are at 5V supply.

The model you are looking at is a simplified transistor level model. Changing parameters is complicated as it would require changing transistor parameters.

Response time does not really change much over supply. The biggest change to speed you would see is if the pull-up voltage was also changing from 5V to 28V, as this changes the contribution of rise and fall times over a wider voltage swing.

0 Nicholas Navarrete 7 months ago in reply to Paul Grohe

Prodigy 10 points

The pullup voltage was also set to 28V, would the rise and fall times change drastically?

0 HO SIU 7 months ago in reply to Nicholas Navarrete

TI__Expert 7580 points

Hi Nicholas,

The pull-up voltage changing to 28V should increase fall time since it would take longer to discharge the output capacitance that was charged to a higher voltage and should decrease rise time since a larger current would flow into the output capacitance.

0 Paul Grohe 7 months ago in reply to Nicholas Navarrete

TI__Guru 54976 points

Hi Nicolas,

See section 6.2 of the LM339 family application note. It explains about the rise time.

Application Design Guidelines for LM339, LM393, TL331 Family Comparators

You could predict the fall-time by using 16 ohms for the resistance value - which is the average equivalent "RDSon" of the output when low.

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LM193-MIL: LM193 28V Pspice model