General Description

The MAX703/MAX704 microprocessor (μP) supervisory circuits reduce the complexity and number of components required for power-supply monitoring and battery control functions in μP systems. These devices significantly improve system reliability and accuracy compared to that obtained with separate ICs or discrete components.

The MAX703/MAX704 are available in 8-pin DIP and SO packages and provide four functions:

?? 1) An active-low reset during power-up, power-down, and

????? brownout conditions.

?? 2) Battery-backup switching for CMOS RAM, CMOS μPs,

????? or other low-power logic circuitry.

?? 3) A 1.25V threshold detector for power-fail warning,

????? low-battery detection, or for monitoring a power supply

????? other than +5V.

?? 4) An active-low manual reset input.

??

The MAX703 and MAX704 differ only in their supplyvolt age monitor levels. The MAX703 generates a reset when the supply drops below 4.65V, while the MAX704 gener ates a reset below 4.40V.

特性 Features

● Battery-Backup Power Switching

● Precision Supply-Voltage Monitor

?? ? 4.65V (MAX703)

?? ? 4.40V (MAX704)

● 200ms Reset Pulse Width

● Debounced TTL/CMOS-Compatible Manual Reset

?? Input

● 200μA Quiescent Current

● 50nA Quiescent Current in Battery-Backup Mode

● Voltage Monitor for Power-Fail or Low-Battery

?? Warning

● 8-Pin DIP and SO Packages

● Guaranteed RESET Assertion to VCC = 1V

Applications

?? ● Computers

?? ● Controllers

?? ● Intelligent Instruments

?? ● Critical μP Power Monitoring