ADA4932-1YCPZ-R2 datasheet(19/27 Pages) AD

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Data Sheet

ADA4932-1/ADA4932-2

Rev. E | Page 19 of 27

THEORY OF OPERATION

The ADA4932-1/ADA4932-2 differ from conventional op amps

in that it has two outputs whose voltages move in opposite

directions and an additional input, VOCM. Like an op amp, it relies

on high open-loop gain and negative feedback to force these

outputs to the desired voltages. The ADA4932-1/ADA4932-2

behave much like standard voltage feedback op amps and

facilitates single-ended-to-differential conversions, common-

mode level shifting, and amplifications of differential signals.

Like an op amp, the ADA4932-1/ADA4932-2 have high input

impedance and low output impedance. Because they use voltage

feedback, the ADA4932-1/ADA4932-2 manifest a nominally

constant gain bandwidth product.

Two feedback loops are employed to control the differential and

common-mode output voltages. The differential feedback, set

with external resistors, controls only the differential output voltage.

The common-mode feedback controls only the common-mode

output voltage. This architecture makes it easy to set the output

common-mode level to any arbitrary value within the specified

limits. The output common-mode voltage is forced, by the internal

common-mode feedback loop, to be equal to the voltage applied

to the VOCM input.

The internal common-mode feedback loop produces outputs

that are highly balanced over a wide frequency range without

requiring tightly matched external components. This results in

differential outputs that are very close to the ideal of being

identical in amplitude and are exactly 180° apart in phase.

ADA4932-1YCPZ-R2 데이터시트(PDF) 19 Page - Analog Devices