LM809 - National Semiconductor

LM809 3-Pin Microprocessor Reset Circuits

The LM809/810 microprocessor supervisory circuits can be used to monitor the power supplies in microprocessor and digital systems. They provide a reset to the microprocessor during power-up, power-down and brown-out conditions. The function of the LM809/810 is to monitor the VCC supply voltage, and assert a reset signal whenever this voltage declines below t.

Features

Precise monitoring of 3V, 3.3V, and 5V supply voltages Superior upgrade to MAX809/810 Fully specified over temperature 140ms min. Power-On Reset pulse width, 240ms typical Active-low RESET Output (LM809) Active-high RESET Output (LM810) n Guaranteed RESET Output valid for VCC≥1V n Low Supply Current, 15µA typ. n Power supply transient immunity n n n n Applications n n n n n n Microprocessor Systems Computers Controllers Intelligent Instruments Portable/Battery-Powered Equipment Automotive Typical Application Circuit Connection Diagram DS101057-2 ( ) are for LM810 DS101057-1 © 1999 Nation.