ASM1233D-L/D/M

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 1.3

Low Power, 5V/3.3V, µP Reset, Active LOW, Open-Drain Output

March 2005

General Description

The ASM1233D-L/1233D/1233M are voltage supervisors with

low-power, 5/3.3V µP Reset, with an active LOW, open-drain

output. Maximum supply current over temperature is 15µA for

3.3V devices and 20µA for 5V devices.

The ASM1233D-L/1233D/1233M generates an active LOW

reset signal whenever the monitored supply is out of tolerance.

A precision reference and comparator circuit monitors power

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 ASM1233D-L/1233D/1233M is designed with an open-

drain output stage and operates over the extended industrial

temperature range. These devices are available in compact

SOT-223, SO-8 and TO-92 packages.

Other low power products in this family include ASM1810/11/

12/15/16/17.

Key Features

•

Low Supply Current

• 15µA maximum (<=3.6V), 20µA maximum (5.5V)

•

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 SOT-223/SO-8/TO-92 packages

•

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

Microprocessor

RESET

RESET

GND

GND

Supply

Reference

Delay

350ms

Typical

Tolerance

Bias

+

-

ASM1233D-L,ASM1233D,ASM1233M

RESET

Delay

Typical

+

-

5.0kΩ