Rainbow Electronics MAX977 User Manual

General description, Applications, Features

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General Description

The MAX975/MAX977 single/dual comparators feature
three different operating modes, and are optimized for
+3V and +5V single-supply applications. The operating
modes are as follows: high speed, high speed with
auto-standby, and low power. Propagation delay is 28ns
in high-speed mode, while supply current is only 250

µ

A.

Supply current is reduced to 3µA in low-power mode.

The auto-standby feature allows the comparator to
automatically change from low-power mode to high-
speed mode upon receipt of an input signal. In the
absence of an input signal, the comparator reverts
back to low-power mode after an adjustable timeout
period. The timeout period for the MAX975 to enter
standby is set by a single capacitor. The dual MAX977
features independently adjustable timeout periods for
each comparator using separate capacitors.

The MAX975/MAX977’s inputs have a common-mode
voltage range of -0.2V to (V

CC

- 1.2V). The differential

input voltage range extends rail to rail. The outputs are
capable of rail-to-rail operation without external pull-up
circuitry, making these devices ideal for interface with
CMOS/TTL logic. All inputs and outputs can tolerate a
continuous short-circuit fault condition to either rail. The
comparator’s internal hysteresis in high-speed mode
ensures clean output switching, even with slow-moving
input signals.

The single MAX975 is available in 8-pin SO and 8-pin

µ

MAX packages, while the dual MAX977 is available in

14-pin SO and 16-pin QSOP packages.

________________________Applications

Battery-Powered Systems

RF ID Tags

Keyless Entry

Threshold Detectors/Discriminators

3V Systems

IR Receivers

Digital-Line Receivers

____________________________Features

Three Operating Modes:

High Speed
High Speed with Auto-Standby
Low Power

28ns Propagation Delay (high-speed mode)

5µA Max Supply Current in Low-Power/
Auto-Standby Modes

+3V/+5V Single-Supply Operation

Rail-to-Rail Outputs

Ground-Sensing Input

Internal Hysteresis (high-speed mode)

Adjustable Timeout Period

µMAX Package (MAX975)
QSOP-16 Package (MAX977)

MAX975/MAX977

Single/Dual, +3V/+5V Dual-Speed

Comparators with Auto-Standby

________________________________________________________________

Maxim Integrated Products

1

Functional Diagram

19-1141; Rev 1; 11/98

PART

MAX975

ESA

MAX975EUA

MAX977

ESD

-40°C to +85°C

-40°C to +85°C

-40°C to +85°C

TEMP. RANGE

PIN-PACKAGE

8 SO

8 µMAX

14 SO

Ordering Information

Pin Configurations appear at end of data sheet.

MAX977EEE

-40°C to +85°C

16 QSOP

MAX975

V

CC

IN+

LP

OUT

GND

STO

HIGH SPEED

LOW POWER

ENABLE

IN-

STAT

TIMING

CIRCUIT

ENABLE

TRANSITION

MONITOR

For free samples & the latest literature: http://www.maxim-ic.com, or phone 1-800-998-8800.
For small orders, phone 1-800-835-8769.

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