Date: 18/02/2009

Integrated µP supervisor circuits provide battery backup and CE gating

Maxim Integrated Products introduced the MAX16016/20/21/23/24 low power (< 1.2µA), microprocessor (µP) supervisory circuits featuring precision power-supply monitoring and battery-control functions. These supervisory circuits integrate features including a µP reset circuit, battery-backup switchover, power-fail warning, and chip-enable (CE) gating. Their integration simplifies designs and minimizes the number of components required for power-supply monitoring. The MAX16016/20/21/23/24 are ideal for applications such as point-of sale (POS) terminals, industrial equipment, fax machines, computers, and set-top boxes.

Some of the key features include:

1. To protect critical data, these devices automatically switch the real-time clock (RTC) or RAM power source to the backup battery when VCC falls below the reset threshold and VBATT.
2. A reset output asserts when VCC is below the reset-threshold voltage and for at least 145ms after VCC returns above its threshold.
3. This reset output prevents code-execution errors during power-up, power-down, and brownout conditions.
4. Each device offers an active-low, push-pull reset or an active-low, open-drain reset.
5. A power-fail comparator signals an interrupt when VPFI falls below 590mV or when VCC falls below the reset threshold.
6. The MAX16016/20/21/24 include a battery-on output during battery-backup mode
7. The MAX16016/20/21 also include a watchdog function that triggers a reset pulse whenever WDI remains high or low for longer than the watchdog-timeout period.
8. The MAX16020/21/24 provide internal gating of the CE signals to prevent erroneous data from corrupting the CMOS RAM.
9. The MAX16023/24 integrate a low-dropout regulator capable of delivering up to 100mA; a manual reset input; and a user-adjustable reset input for monitoring a second voltage.
10. The MAX16016/20/21/23/24 consume only 1.2µA of quiescent current and operate from as low as 1.53V.
11. Fully specified over the -40°C to +85°C extended temperature range

Package: available in 8-/10-pin TDFN or 16-pin TQFN packages.
Price: starts at $2.48 (1000-up, FOB USA).

For more information, go to www.maxim-ic.com