Maxim Integrated Products has introduced ultra-low-power microprocessor supervisory circuits that monitor a single system supply voltage and consume 125 nA supply current to extend battery life in power-sensitive applications.

The MAX16056-MAX16059 feature capacitor-adjustable watchdog (MAX16056/MAX16058) and reset timeouts to maximize design flexibility. The configurability makes it easy for designers to quickly change design parameters, and enables the supervisors to be used in power-saving schemes.

Because of their ultra-low power consumption and flexible timeout configuration, the devices can be utilized in multiple ways within the system while saving board space. The MAX16056-MAX16059 are well suited for battery-powered devices, handheld electronics, metering equipment, and other applications where battery life is crucial.

Many microprocessors in battery-powered systems spend the majority of their time in standby/sleep mode, only waking up periodically to perform a required function. In these applications, standby current consumption is often the most important factor in determining battery life, as the application may spend as much as 99 percent of the day in sleep mode.

To minimize system power consumption in these applications, the MAX16056-MAX16059 can be used to periodically wake up the processor to complete its required duties, and then turn off the processor when those functions are complete. At 125 nA, the operating supply current of these supervisory circuits is much lower than the standby supply current of a typical microcontroller (>1 microamp). The MAX16056-MAX16059 makes a negligible impact on the application's power budget, effectively reducing system shutdown current to zero. Altogether, these supervisors can increase battery life by several months in low-power applications.

The MAX16056-MAX16059 can also be used as low-power oscillators to conserve energy, as they consume much less power than integrated adjustable oscillators.

The MAX16056-MAX16059 can monitor voltages from 1.575 V to 4.625 V. The devices assert a reset signal whenever the Vcc supply voltage drops below the reset threshold, manual reset is pulled low, or the watchdog timer (MAX16056/MAX16058) runs out. The reset function features immunity to power-supply transients.

Availability and Pricing

The MAX16056-MAX16059 operate from a 1.1 V to 5.5 V voltage range, and are available in either push-pull or open-drain output configurations. A manual-reset input facilitates testing.

All devices are fully specified over the -40 degrees Celsius to +125 degrees Celsius automotive temperature range. The MAX16056/MAX16058 are available in a 3mm x 3mm, 8-pin TDFN package, and the MAX16057/MAX16059 are available in a 3 mm x 3 mm, 6-pin TDFN package. Prices start at $1.10 (1000-up, FOB USA). Samples are now available.

Datasheet: MAX16056-MAX16059