Data Sheet

ADA4522-1/ADA4522-

2/ADA4522-4

analog.com

Rev I 41 of 48

comparator to save board space and cost; however, this is not recommended for the ADA4522-1/ADA4522-2/

ADA4522-4.

Figure 86

and Figure 87 show the ADA4522-1/ADA4522-2/ADA4522-4 configured as a comparator, with 10 kΩ resistors

in series with the input pins. Any unused channels are configured as buffers with the input voltage kept at the

midpoint of the power supplies. The ADA4522-1/ADA4522-2/ADA4522-4 have input devices that are protected from

large differential input voltages by Diode D5 and Diode D6, as shown in Figure 72. These diodes consist of substrate

PNP bipolar transistors, and conduct whenever the differential input voltage exceeds approximately 600 mV;

however, these diodes also allow a current path from the input to the lower supply rail, resulting in an increase in the

total supply current of the system. Both comparator configurations yield the same result. At 30 V of power supply,

ISY+ remains at 1.55 mA per dual amplifier, but ISY− increases close to 2 mA in magnitude per dual amplifier.

Figure 86.Comparator Configuration A

Figure 87.Comparator Configuration B

ADA4522-1/

ADA4522-2/

ADA4522-4

A1

10kΩ

10kΩ

ISY+

+VSY

VOUT

–VSY

ISY–

A2

A1

10kΩ

10kΩ

ISY+

+VSY

VOUT

–VSY

ISY–

A2

ADA4522-1/

ADA4522-2/

ADA4522-4