LP3470 Datasheet, PDF (1/8 Pages) National Semiconductor (TI) – Tiny Power On Reset Circuit

September 2000
LP3470
Tiny Power On Reset Circuit
General Description
The LP3470 is a micropower CMOS voltage supervisory
circuit designed to monitor power supplies in microprocessor
(µP) and other digital systems. It provides maximum adjust-
ability for power-on-reset (POR) and supervisory functions. It
is available in the following six standard reset threshold
voltage (V_RTH) options: 2.63V, 2.93V, 3.08V, 3.65V, 4.00V,
4.38V, and 4.63V. If other voltage options between 2.4V and
5.0V are desired please contact your National Semiconduc-
tor representative.
The LP3470 asserts a reset signal whenever the V_CC supply
voltage falls below a reset threshold. The reset time-out
period is adjustable using an external capacitor. Reset re-
mains asserted for an interval (programmed by an external
capacitor) after V_CC has risen above the threshold voltage.
The device is available in the tiny SOT23-5 package.
Key Specifications
n ±1% Reset Threshold Accuracy Over Temperature
n Standard Reset Threshold Voltages: 2.63V, 2.93V,
3.08V, 3.65V, 4.00V, 4.38V, and 4.63V
n Custom Reset Threshold Voltages: For other voltages
between 2.4V and 5.0V contact your National
Semiconductor representative
n Very Low Quiescent Current (16 µA typical)
n Guaranteed Reset valid down to V_CC=0.5V
Features
n Tiny SOT23-5 Package
n Open Drain Reset Output
n Programmable Reset Timeout Period Using an External
Capacitor
n Immune to Short V_CC Transients
Applications
n Critical µP and µC Power Monitoring
n Intelligent Instruments
n Computers
n Portable/Battery-Powered Equipments
Pin Configuration and Basic Operating Circuit
Pin Configuration
Basic Operating Circuit
10001602
Top View
See NS Package Number
MF05A
10001601
© 2004 National Semiconductor Corporation DS100016
www.national.com