DocID026915 Rev 1

9/19

AN4586

2-op amp instrumentation amplifier

19

Figure 5 shows where the second condition has not been met and the first op amp has

become saturated.

Figure 5. 2-op amp instrumentation amplifier example

In Figure 5, with Vcc = 5 V

Thus, we do not have

This means that the first op amp is saturated and Vout2 is not equal to the expected value:

(4.3 V - 4.2 V) * (1 + 10 k / 2 k) = 0.6 V.

Vcc

1

Rf1

Rg1

-----------

+

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

4.17 V

=

V1

Vcc

1

Rf1

Rg1

-----------

+

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

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