This wideband FDA requires external
resistors for correct signal-path operation. When configured for the desired input impedance
and gain setting with these external resistors, the amplifier can be either
on with the
PD pin asserted to a voltage greater than (Vs–) + 1.7 V, or turned
off by asserting
PD low. Disabling the amplifier shuts off the
quiescent current and stops correct amplifier operation. The signal path is still present for
the source signal through the external resistors.
The Vocm control pin sets the output average
voltage. If left open, Vocm defaults to an internal midsupply value. Driving this
high-impedance input with a voltage reference within the valid range sets a target for the
internal Vcm error amplifier.