AD827
Figure 19. Crosstalk vs. Frequency
Figure 20. Crosstalk Test Circuit
INPUT PROTECTION PRECAUTIONS
An input resistor (resistor R
IN
of Figure 21a) is recommended in
circuits where the input common-mode voltage to the AD827
may exceed (on a transient basis) the positive supply voltage.
This resistor provides protection for the input transistors by
limiting the maximum current that can be forced into their
bases.
For high performance circuits, it is recommended that a second
resistor (R
B
in Figures 21a and 22a) be used to reduce bias-
current errors by matching the impedance at each input. This
resistor reduces the error caused by offset voltages by more than
an order of magnitude.
Figure 21a. Follower Connection
Figure 21b. Follower Large Signal
Pulse Response
Figure 21c. Follower Small
Signal Pulse Response
Figure 22a. Inverter Connection
Figure 22b. Inverter Large Signal
Pulse Response
Figure 22c. Inverter Small
Signal Pulse Response
–6–
REV. B
AD [ ANALOG DEVICES ]
