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© 2007 by Catalyst Semiconductor, Inc.

Characteristics subject to change without notice

Doc. No. 3026, Rev. B

CAT853, CAT863

CAT859, CAT869

3-Pin Microprocessor Power Supply

Supervisors

FEATURES

Precision monitoring of +3.3V (-5%, -10%), 5V

(-10% Power Supplies)

Active low reset output

6μA power supply current

Power supply transient immunity

Industrial temperature range: -40ºC to +85ºC

RoHS-compliant SOT-23 package

APPLICATIONS

Computers

Servers

Laptops

Cable modems

Wireless communications

Embedded control systems

White goods

Power meters

Intelligent instruments

PDAs and handheld equipment

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DESCRIPTION

The CAT853, CAT863, CAT859, and CAT869 are

supervisory circuits that monitor power supplies in digital

systems.

These devices generate a reset signal, which is asserted

while the power supply voltage is below a preset threshold

level and for at least 140 ms after the power supply level

has risen above that level. Industry standard threshold

levels are offered to support +3.3V or 5.0V systems.

The CAT859 and CAT869 feature a RESET push-pull

output (active low) for the two pinout options.

The CAT853 and CAT863 feature an open drain RESET

output (active low). Both require a pull-up resistor on

the RESET output.

Fast transients on the power supply are ignored and

levels as low as 1.0V.

PIN CONFIGURATION

THRESHOLD SUFFIX SELECTOR

Nominal Threshold

Voltage

Threshold Suffix

Designation

3.08V

T

2.93V

S

4.38V

M

For Ordering Information details, see page 8.

PIN DESCRIPTIONS

Name

Description

GND

Ground

Power supply voltage that is monitored.

2

CAT853

CAT859

GND

RESET

3-Lead SOT23

1

3

3-Lead SOT23

CAT863

CAT869

GND

RESET

1

2

3