General Description

The MAX6819/MAX6820 are power-supply sequencers for dual-voltage microprocessors (µPs) and multivoltage systems. These devices monitor a primary supply voltage and enable/disable an external n-channel MOSFET switch for a secondary supply voltage. The MAX6819/MAX6820 control local component voltage sequencing when system power-on/power-off characteristics cannot be guaranteed (supplies come from a multivoltage system bus, silver box, or must be sequenced in different modes for components on the same board). These small power-supply sequencers improve system reliability.

Features

♦ Adjustable Primary Supply Voltage Monitor

   (Monitors Down to 0.62V)

♦ Internal Charge Pump to Enhance External

   Secondary Supply n-Channel MOSFET Switch

♦ Delay from Primary Supply Good to Secondary

   Supply Enabled

   Factory Fixed 200ms (MAX6819)

   Capacitor Adjustable (MAX6820)

♦ Logic Driven ENABLE Input (MAX6819)

♦ Immune to Short Voltage Transients

♦ Few External Components

♦ -40°C to +125°C Operating Temperature Range

♦ Small 6-Pin SOT23 Package

Applications

   Dual-Voltage Microprocessors

   Multivoltage Systems

   Digital Signal Processors

   Power PC™ Series Processors