General Description

The MAX814/MAX815/MAX816 are high-accuracy microprocessor (µP) supervisory circuits that provide power-on reset, watchdog, and power-fail functions. They eliminate manual trimming and improve reliability in critical applications needing high-accuracy reset thresholds. The RESET output is guaranteed to be in the correct state for VCC down to 1V. The reset comparator is designed to ignore fast transients on VCC. Reset thresholds are available for operation with a variety of 3V and 5V supply voltages.

A 75µA maximum supply current makes the MAX814/MAX815/MAX816 ideal for use in portable equipment. All three devices are available in 8-pin DIP and SO packages. See the Selector Table for a review of features.

Features

♦ ±1 Worst-Case Reset Threshold Accuracy

♦ 4.8V, 4.7V, 4.55V, 3.03V, or Adjustable Reset Thresholds

♦ ±1 Low-Line Threshold Accuracy (MAX814)

   60mV Above Reset Threshold

♦ 200ms Reset Time Delay

♦ Active-Low RESET Output

   Active-High RESET Output (MAX814/MAX816)

♦ 75µA Max Supply Current

♦ Guaranteed RESET Valid to VCC = 1V

♦ Manual Reset Input

♦ ±2 Power-Fail Comparator

♦ Independent Watchdog with 1.56sec Timeout (MAX815)

♦ Power-Supply Glitch Immunity

♦ 8-Pin SO and DIP Packages

Applications

   Medical Equipment

   Controllers

   Intelligent Instruments

   Critical µP Power Monitoring

   Portable/Battery-Powered Equipment

   Set-Top Boxes