June 1999

1

MIC2753/2754

MIC2753/2754

Micrel

MIC2753/2754

Power Supply Supervisors

Preliminary Information

General Description

The MIC2753 and MIC2754 are ultraminiature, full-featured,

power supply supervisors featuring active-high and active-

low reset outputs, respectively.

The MIC2753/4 includes an undervoltage detector with a

power-on reset generator and reset output, an overvoltage

detector with a separate output for activating crowbar circuits,

and a debounced manual reset input. Typical supply current

is a low 30

µA.

These devices provide a 140ms minimum reset output at

power-on and assert their reset outputs any time the input

voltage deviates beyond preset overvoltage or undervoltage

thresholds. Reset outputs remain asserted for 140ms (mini-

mum) after the input returns to normal or after releasing the

manual reset. When an overvoltage condition is detected, the

overvoltage output is immediately activated. Hysteresis on

both thresholds prevents erratic operation due to noise.

Typical Application

Microcontroller

Manual

Reset

MIC2754

VCC

HV

MR

RST

VIN

RST IN

GND

GND

Fuse

SCR

Crowbar

Micrel, Inc. • 1849 Fortune Drive • San Jose, CA 95131 • USA • tel + 1 (408) 944-0800 • fax + 1 (408) 944-0970 • http://www.micrel.com

Features

• Undervoltage and overvoltage monitor

• Separate overvoltage flag output

• Generates 140ms (minimum) power-on reset pulse

• Debounced manual reset input

• Choice of active-high (MIC2753) or

active-low (MIC2754) reset outputs

• Low 30

µA typical supply current

• No external components needed

• IttyBitty™ SOT-23-5 package

Applications

• Computer systems

• Embedded controllers

• Power supplies

• Telecommunications systems