Power Supervisory Circuits Work At 220 nA

Eyeing battery-powered applications using low-power DSPs, microcontrollers and microprocessors, the TPS383x family of power supervisory circuits has been introduced as the first such ICs in the industry to operate at 220 nA. This is said to be about one quarter of the power of competing products. Versions of the device precisely monitor 1.8V, 2.5V, 3V and 3.3V power supplies. No external components for voltage monitoring or delay time generation are needed.
Relying on a built-in capacitive power source, the devices monitor rail voltages while in standby mode, allowing it to wake up and reset the processor in case of a failure. Depending on the device, reset options include active-low push/pull, active-high push/pull, and active-low open drain. A manual reset function affords user operation and supports daisy chaining of multiple ICs. Other features include a selectable delay time of 10 or 200 ms and trip-point accuracy to within ±2.5%. Available in five-pin SOT-23 packages, pricing is $0.93 each/1,000.