REV. D

Information furnished by Analog Devices is believed to be accurate and

reliable. However, no responsibility is assumed by Analog Devices for its

use, nor for any infringements of patents or other rights of third parties that

may result from its use. No license is granted by implication or otherwise

under any patent or patent rights of Analog Devices.

a

Fast, Precision

Comparator

AD790

FEATURES

45 ns max Propagation Delay

Single 5 V or Dual

15 V Supply Operation

CMOS or TTL Compatible Output

250

V max Input Offset Voltage

500

V max Input Hysteresis Voltage

15 V max Differential Input Voltage

Onboard Latch

60 mW Power Dissipation

Available in 8-Pin Plastic and Hermetic Cerdip

Packages

Available in Tape and Reel in Accordance with

EIA-481A Standard

APPLICATIONS

Zero-Crossing Detectors

Overvoltage Detectors

Pulse-Width Modulators

Precision Rectifiers

Discrete A/D Converters

Delta-Sigma Modulator A/Ds

PRODUCT DESCRIPTION

The AD790 is a fast (45 ns), precise voltage comparator, with a

number of features that make it exceptionally versatile and easy

to use. The AD790 may operate from either a single 5 V supply

or a dual

±15 V supply. In the single-supply mode, the AD790’s

inputs may be referred to ground, a feature not found in other

comparators. In the dual-supply mode it has the unique ability

of handling a maximum differential voltage of 15 V across its in-

put terminals, easing their interfacing to large amplitude and

dynamic signals.

This device is fabricated using Analog Devices’ Complementary

Bipolar (CB) process—which gives the AD790’s combination

of fast response time and outstanding input voltage resolution

(1 mV max). To preserve its speed and accuracy, the AD790

incorporates a “low glitch” output stage that does not exhibit

the large current spikes normally found in TTL or CMOS output

stages. Its controlled switching reduces power supply disturbances

that can feed back to the input and cause undesired oscillations.

The AD790 also has a latching function which makes it suitable

for applications requiring synchronous operation.

The AD790 is available in five performance grades. The

AD790J and the AD790K are rated over the commercial tem-

perature range of 0

°C to 70°C. The AD790A and AD790B are

rated over the industrial temperature range of –40

°C to +85°C.

The AD790S is rated over the military temperature range of

–55

°C to +125°C.

PRODUCT HIGHLIGHTS

1. The AD790’s combination of speed, precision, versatility

and low cost makes it suitable as a general purpose compara-

tor in analog signal processing and data acquisition systems.

2. Built-in hysteresis and a low-glitch output stage minimize the

chance of unwanted oscillations, making the AD790 easier to

use than standard open-loop comparators.

3. The hysteresis combined with a wide input voltage range

enables the AD790 to respond to both slow, low level (e.g.,

10 mV) signals and fast, large amplitude (e.g., 10 V) signals.

4. A wide variety of supply voltages is acceptable for operation

of the AD790, ranging from single 5 V to dual +5 V/–12 V,

±5 V, or +5 V/±15 V supplies.

5. The AD790’s power dissipation is the lowest of any compara-

tor in its speed range.

and ground, thus providing a predictable output under a

wide range of input and output conditions.

CONNECTION DIAGRAMS

8-Pin Plastic Mini-DIP (N)

and Cerdip (Q) Packages

OUTPUT

LATCH

GROUND

1

2

3

45

6

7

8

AD790

–

+

+IN

–IN

8-Pin SOIC (R) Package

LATCH

GROUND

1

2

3

4

5

6

7

8

OUTPUT

AD790

–

+IN

–IN

One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A.

Tel: 781/329-4700

www.analog.com

Fax: 781/326-8703

© Analog Devices, Inc., 2002