Sunnyvale, Calif.Maxim Integrated Products has introduced the MAX16016/20/21/23/24 low-power (< 1.2microamps), microprocessor supervisory circuits, featuring precision power-supply monitoring and battery-control functions.
In small TQFN or TDFN packages, these supervisory circuits integrate a variety of features including a microprocessor reset circuit, battery-backup switchover, power-fail warning, and chip-enable (CE) gating. Their high integration simplifies designs and minimizes the number of components required for power-supply monitoring. Applications include point-of sale (POS) terminals, industrial equipment, fax machines, computers, and set-top boxes.
To protect critical data, the 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. A reset output asserts when Vcc is below the reset-threshold voltage and for at least 145ms after Vcc returns above its threshold. This reset output prevents code-execution errors during power-up, power-down, and brownout conditions. Each device offers an active-low, push-pull reset or an active-low, open-drain reset. A power-fail comparator signals an interrupt when Vpfi falls below 590mV or when Vcc falls below the reset threshold.
The MAX16016/20/21/24 include a battery-on output during battery-backup mode; 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. The MAX16020/21/24 provide internal gating of the CE signals to prevent erroneous data from corrupting the CMOS RAM. 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.
The MAX16016/20/21/23/24 consume 1.2-microamps of quiescent current and operate from as low as 1.53V. Fully specified over the -40°C to +85°C extended temperature range, they are available in 8-/10-pin TDFN or 16-pin TQFN packages.
Maxim Integrated Products, www.maxim-ic.com