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OPA171: OPA171

Part Number: OPA171
Other Parts Discussed in Thread: TLV9301, OPA202, LM5575,

Tool/software:

Hello TI Team, 

 

we are currently measuring a small signal with OPA171AIDBVT. Below the schematic.

We wanted to have more alternative options so we added two new more part numbers:

TLV9301
OPA202

 

Additional we have two types of waveforms in the design for the Vcc=5V. The 5V supply is generating from LM5575. 

The first one creates no issues to the output measurement.

 

But there is an issue with the second waveform. 

By changing the input voltage of the LM5575 (from 15V to 60V) the maximum voltage of the spike is increased about 250mV at full range and the frequency of these spikes from 119kHz to 46kHz at full voltage range.

Now there is a change in the output voltage of the op-amp when changing the input voltage from 15V to 60V and this causes problems to some measurements.

This disturbance is only visible at OPA202. (ΔVos ~ 145mV from 15V to 60V change)

The other two op-amps are very immune to these changes. 

OPA171 (ΔVos ~ 3mV from 15V to 60V change)

TLV9301 (ΔVos ~ 145mV from 15V to 60V change)

 

What parameter of the op-amp datasheet should we consider in order to have an alternative that will not create any issues?

 

Regards,

KT