RHF310

Bias of an inverting amplifier

Doc ID 15577 Rev 3

17/22

6

Bias of an inverting amplifier

A resistance is necessary to achieve good input biasing, such as resistance R shown in

Figure 26.

The value of this resistance is calculated from the negative and positive input bias current.

The aim is to compensate for the offset bias current, which can affect the input offset voltage

R is:

Figure 26.

Compensation of the input bias current

R

R

in

R

fb

×

R

in

R

+

fb

-----------------------

=

R

Load

Output

R

fb

R

in

I

ib

-

I

ib

+

V

V

CC

-

+

_

AM00839