OPA4863: Can't find input capacitance values

Rishabh Maurya

Part Number: OPA4863

Tool/software:

I am making a TIA using the OPA4863 operational amplifier. I need the common mode and differential capacitance values to determine the appropriate capacitance value for the feedback resistor. Unfortunately, the datasheet doesn't explicitly mention these capacitance values. I have also looked at datasheets of other op amps from TI, and they don't seem to mention these values either. Is there a way to find or estimate these capacitance values for the OPA4863? If not directly available, are there any recommended methods or calculations to estimate these values?

over 1 year ago

0 Alec Saebeler over 1 year ago

TI__Mastermind 24524 points

Hello Rishabh,

You can find the common-mode and differential impedance values in the Input table in the Electrical Characteristics section of the OPAx863 datasheet:

The capacitance values are listed in pF. We do not specify separate resistance and capacitance values, as we include them together in 'input impedance' values.

Best,

Alec

0 Aditya Gosavi over 1 year ago

TI__Intellectual 2065 points

Hi Rishabh,

You can take a look at the tool we have developed: Analog circuit design studio, ("Trans-impedance amplifer" tool) where the input cap of OpAmp (C_cm + C_dm) is integrated in the tool and you can see that in the "OpAmp Specifications" tab (under the name C_AMP) of the tool.

Thanks

Aditya Gosavi

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OPA4863: Can't find input capacitance values