Low-Power Battery-Backup Circuits in Small µDFN Packages

The MAX16033–MAX16040 supervisory circuits reduce the complexity and number of components required for power-supply monitoring and battery-control functions in microprocessor (µP) systems. The devices significantly improve system reliability and accuracy compared to other ICs or discrete components. The MAX16033–MAX16040 provide µP reset, backup-battery switchover, power-fail warning, watchdog, and chip-enable gating features.

The MAX16033–MAX16040 operate from supply voltages up to 5.5V. The factory-set reset threshold voltage ranges from 2.32V to 4.63V. The devices feature a manual-reset input (MAX16033/MAX16037), a watchdog timer input (MAX16034/MAX16038), a battery-on output (MAX16035/MAX16039), an auxiliary adjustable reset input (MAX16036/MAX16040), and chip-enable gating (MAX16033–MAX16036). Each device includes a power-fail comparator and offers an active-low push-pull reset or an active-low open-drain reset.

The MAX16033–MAX16040 are available in 2mm x 2mm, 8-pin or 10-pin µDFN packages and are fully specified from -40°C to +85°C.

Applications

* Portable/Battery-Powered Equipment * POS Equipment * Critical µP/µC Power Monitoring * Set-Top Boxes * Controllers * Computers * Fax Machines * Industrial Control * Real-Time Clocks * Intelligent Instruments

* Low 1.2V Operating Supply Voltage

* Precision Monitoring of 5.0V, 3.3V, 3.0V, and 2.5V Power-Supply Voltages

* Independent Power-Fail Comparator

* Debounced Manual-Reset Input

* Watchdog Timer, 1.6s Timeout

* Battery-On Output Indicator

* Auxiliary User-Adjustable RESETIN

* Low 13µA Quiescent Supply Current

* Two Available Output Structures:

* Active-Low Push-Pull Reset

* Active-Low Open-Drain Reset

* Active-Low Reset Valid Down to 1.2V

* Power-Supply Transient Immunity

* 140ms (min) Reset Timeout Period

* Small 2mm x 2mm, 8-Pin and 10-Pin µDFN Packages