Microprocessor supervisory circuit monitors system voltage with programmable delay

The PT7M3808 family of microprocessor supervisory circuits introduced by Diodes Incorporated monitors system voltages from 0.4V to 5.0V.

With threshold accuracy from 0.5% and an adjustable delay time from 1.25ms to 10ms, these small form-factor devices enable power-on reset functionality for microprocessor and other digital systems while consuming minimal power.

Applications include notebook and desktop computers, and battery-powered portable equipment for markets ranging from data centres to security systems.

Offered in fixed-threshold versions for standard voltage rails between 0.9V and 5V, and with an adjustable threshold version down to 0.4V, the PT7M3808 uses a precision reference to provide a 0.5% negative-going input threshold accuracy when monitoring voltages up to 3.3V and 1% accuracy at voltages from 3.3V to 5.0V.

The delay time is adjusted from 1.25ms to 10ms by connecting an external capacitor to the CT pin; a longer 20ms delay can be achieved by disconnecting the CT pin, while a 300ms delay is possible by connecting the CT pin to VDD with a resistor.

The PT7M3808 has a very low quiescent current, typically 2.8A, making it well-suited for battery-powered applications.

Available in SOT26 and DFN2020-6 packages, the PT7M3808 takes up very little board space for both new and drop-in replacement designs.