ASM1233M

Alliance Semiconductor

2575 Augustine Drive . Santa Clara, CA 95054 . Tel: 408.855.4900 . Fax: 408.855.4999 . www.alsc.com

Notice: The information in this document is subject to change without notice

rev 1.0

Low Power, 5V/3.0V, µP Reset, Active LOW, Open-Drain Output

October 2003

General Description

The ASM1233M is a voltage supervisor with low-power, 5V µP

Reset, with an active LOW, open-drain output. Maximum supply

current over temperature is a low 20µA.

The ASM1233M generates an active LOW reset signal

whenever the monitored supply is out of tolerance. A precision

level. Tolerance level options are 5% ,and 10% for a 5V power

supply. The tolerance is 15% for the 3.3V, ASM1233M. When

an out-of-tolerance condition is detected, an internal power-fail

signal is generated which forces an active LOW reset signal.

remains active for 350ms to allow the power supply and system

microprocessor to stabilize.

The ASM1233M is designed with a open-drain output stage and

operates over the extended industrial temperature range.

Devices are available in compact surface mount SO-8

packages and 3-lead TO-92 packages.

Other low power products in this family include the ASM1810/

11/12/15/16/17 and ASM1233D.

Key Features

•

Low Supply Current

•20 µA maximum (5.5 V)

•15µA maximum (3.6 V)

•

Automatically restarts a microprocessor after power failure

•

dition

•

Active LOW power-up reset, 5k

Ω internal pull-up

•

Precision temperature-compensated voltage reference and

comparator

•

Eliminates external components

•

Low-cost TO-92 package

•

Compact surface mount SO-8 package

•

Operating temperature -40°C to +85°C

Applications

•

Set-top boxes

•

Cellular phones

•PDAs

•

Energy management systems

•

Embedded control systems

•

Printers

•

Single board computers

Typical Operating Circuit

Block Diagram

GND

Supply

Reference

Delay

150ms

Typical

Tolerance

Bias

+

-

Microprocessor

ASM1233M

RESET

Delay

150ms

Typical

+

-

1

2

4

RESET

RESET

GND

ASM1233M

5.0kΩ