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TINA/Spice/OPA454: Output Voltage Falling Below 10V

Russell Wetherley1

Expert 4255 points

Part Number: OPA454
Other Parts Discussed in Thread: TINA-TI,

Tool/software: TINA-TI or Spice Models

Hello E2E,

I have a customer using the OPA454 TINA Model in the following configuration:

They have the opamp set up in a non-inverting configuration with a gain of 4. The input signal is from 0-10V. Your power rail is 0-45V. Everything is fine until the output goes below 10V (input of 2.5V). When this happens, the gain starts falling off. They are using 30k and 10k resistors. Any idea why this would be happening? Is this something to do with the simulation model, or are there known errors in the opamp?

Thank you very much!

Russell

over 7 years ago

0 Hooman Hashemi over 7 years ago

TI__Mastermind 22825 points

Hi Russel,

I've changed the TINA-TI reference design for OPA454 to match your conditions and I don't see the issue you are referring to!

Plot below shows output at 6V (<10V you've seen issues).

Here is the reference circuit modified to your conditions:

OPA454 Swing to les than 10V 2_20_17.TSC

May be you can supply the TINA-TI schematic you are having problems with?

Regards,

Hooman

0 Hooman Hashemi over 7 years ago in reply to Hooman Hashemi

TI__Mastermind 22825 points

Hi Russel,

Sounds like you are running into input CM voltage range limitation (which is 2.5V away from either supply rail):

The input(s) should always be higher 2.5V and lower than 42.5V if you are running the part with a single +45V power supply.

Regards,

Hooman