Input Bias Current vs Input Impedance

MichaelH

Hello,

I was wondering if anyone might be able to explain the relationship between the "input bias current" spec and the "input impedance" spec. Is there a way to calculate the total input bias current using the specs from the datasheet, or is it a very nonlinear/non constant?

-Mike

over 9 years ago

0 Marek Lis over 9 years ago

TI__Guru 60610 points

Mike,

The common-mode input resistance may be calculated from the slope of the Input Bias Current vs Input Common-Mode Voltage graph - only the linear portion of the curve, corresponding to specified input common-mode voltage range, must be used.

0 Bruce Trump over 9 years ago in reply to Marek Lis

Guru 21975 points

Mike,

This blog may provide some insight:

“I Need High Input Impedance!” input impedance vs. input bias current

Regards-- Bruce

Amplifiers

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Input Bias Current vs Input Impedance