Diodes Incorporated announced the PT7M3808 family of microprocessor supervisory circuits. These devices monitor system voltages from 0.4 V to 5.0 V, and feature threshold accuracy from 0.5% and an adjustable delay time from 1.25 ms to 10 ms; this allows these small form-factor devices to enable power-on reset functionality for microprocessor and other digital systems while also consuming minimal power. Applications include notebook and desktop computers, and battery-powered portable equipment for markets ranging from data centers to security systems.
Offered in fixed-threshold versions for standard voltage rails between 0.9 V and 5.0 V, and with an adjustable threshold version down to 0.4 V, the PT7M3808 uses a precision reference to provide a 0.5% negative-going input threshold accuracy when monitoring voltages up to 3.3 V and 1% accuracy at voltages from 3.3 V to 5.0 V. The delay time is adjusted from 1.25 ms to 10 ms by connecting an external capacitor to the pin; a longer 20 ms delay can be achieved by disconnecting the CT pin, while a 300 ms delay is possible by connecting the CT pin to VDD with a resistor.
 |
 |
|
| Adjustable Voltage Diagram. | Fixed Voltage Diagram. |
The PT7M3808 has a very low quiescent current, typically 2.8 μA, 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.
