AD604ARSZ-R7 datasheet(17/32 Pages) AD

17 / 32 page

AD604

Rev. D | Page 17 of 32

The AFA offers additional features:

•

The ability to invert the signal by switching the positive

and negative inputs to the ladder network.

•

The possibility of using the DSX1 input as a second

signal input.

•

Fully differential high impedance inputs when both

preamplifiers are used with one DSX (the other DSX could

still be used alone).

•

Independent control of the DSX common-mode voltage.

Under normal operating conditions, it is best to connect a

decoupling capacitor to VOCM, in which case, the common-

mode voltage of the DSX is half the supply voltage; which allows

for maximum signal swing. Nevertheless, the common-mode

voltage can be shifted up or down by directly applying a voltage

to VOCM. It can also be used as another signal input, the only

limitation being the rather low slew rate of the VOCM buffer.

If the dc level of the output signal is not critical, another coupling

capacitor is normally used at the output of the DSX; again this is

done for level shifting and to eliminate any dc offsets contributed

by the DSX (see the AC Coupling section).

AD604ARSZ-R7 Datasheet(PDF) 17 Page - Analog Devices