Supervisor ICs monitor under voltage conditions

Analog Devices Inc. has released new low-power microprocessor supervisory circuits for monitoring under-voltage conditions in handheld industrial instruments, telecommunications devices and other portable applications.

The ADM6326, ADM6328, ADM6346 and ADM6348 supervisory circuits feature an ultralow 500nA supply current that can extend the battery life of mobile devices. The new circuits provide a low-power option for the precision monitoring of DSP, ASIC, FPGA and other processor power supplies to detect under-voltage conditions that can lead to system failure. The supervisory ICs monitor 2.5-, 3-, 3.3- and 5V voltage rails. The ADM6326, ADM6328, ADM6346 and ADM6348 provide a reset output during power-up, power-down and brownout conditions. On power-up, an internal timer holds reset asserted for at least 100ms, which effectively holds the microprocessor in a reset state until conditions have stabilized.

The ADM6326 and ADM6346 have an active low push-pull reset output. The ADM6328 and ADM6348 have an active low open-drain output, which requires an external pull-up resistor. The reset output remains operational with Vcc as low as 1V. The reset comparator features built-in glitch immunity, making it impervious to fast transient on Vcc. Twenty-four reset threshold voltage options are available, in increments between 2.2V and 4.63V, making these devices suitable for monitoring a variety of supplies.

The ADM6326, ADM6328, ADM6346 and ADM6348 are available in a space saving 3-lead SOT-23 package and operate over the extended temperature range of -40°C to +85°C.

As part of a complete signal chain the ADM6326, ADM6328, ADM6346 and ADM6348 supervisory circuits are compatible with ADI's ADP2503 and ADP2504 DC/DC converters, ADP2121 switching regulator and the ADP121 LDO.

Samples of ADM6326, ADM6328, ADM6346 and ADM6348 supervisory circuits in a 3-lead SOT-23 package are all available now. Price each per 1,000 units is $0.95.

- Paul Buckley
Power Management DesignLine Europe

For application notes on supervisor ICs click here.