September 2003
rev 1.0
ASM1233D
Low Power, 5µP Reset, Active LOW, Open-Drain Output
Applications
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Set-top boxes
Cellular phones
PDAs
Energy management systems
Embedded control systems
Printers
Single board computers
General Description
The ASM1233D is a voltage supervisory device with low-power,
5V µP Reset, and an active LOW, open-drain output. Maximum
supply current over temperature is a low 20µA.
The ASM1233D generates an active LOW reset signal
whenever the monitored supply is out of tolerance. A precision
reference and comparator circuit monitor power supply (V
CC
)
level. Tolerance level options are 5%, 10% and 15%. When an
out-of-tolerance condition is detected, an internal power-fail
signal is generated which forces an active LOW reset signal.
After V
CC
returns to an in-tolerance condition, the reset signal
remains active for 350ms to allow the power supply and system
microprocessor to stabilize.
The ASM1233D is designed with a open-drain output stage and
operates over the extended industrial temperature range.
Devices are available in compact surface mount SOT-223
packages and 3-lead TO-92 packages.
Other low power products in this family include the ASM1810/
11/12/15/16/17 and ASM1233M.
Typical Operating Circuit
V
CC
ASM1233D
Microprocessor
RESET
RESET
GND
Key Features
•
Low Supply Current
•20 µA maximum (5.5 V)
•15µA maximum (3.6 V)
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Automatically restarts a microprocessor after power failure
350ms reset delay after V
CC
returns to an in-tolerance con-
dition
Active LOW power-up reset, 5kΩ internal pull-up
Precision temperature-compensated voltage reference and
comparator
Eliminates external components
Low-cost TO-92 package
Compact surface mount SOT-223 package
Operating temperature -40°C to +85°C
1
GND
Reference
Supply
Tolerance
Bias
Block Diagram
V
CC
3
ASM1233D
5.0kΩ
2
RESET
+
-
Delay
150ms
Typical
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
PULSECORE [ PulseCore Semiconductor ]
