Low-quiescent current supervisor with programmable delay & manual reset

The TPS3808 family of microprocessor supervisory circuits monitors system voltages from 0.4 V to 5 V, asserting an open-drain RESET signal when the SENSE voltage drops below a preset threshold or when the manual reset ( MR) pin drops to a logic low. The RESET output remains low for the user-adjustable delay time after the SENSE voltage and manual reset ( MR) return above the respective thresholds.

The TPS3808 device uses a precision reference to achieve 0.5% threshold accuracy for VIT ≤ 3.3 V. The reset delay time can be set to 20 ms by disconnecting the CT pin, 300 ms by connecting the CT pin to VDD using a resistor, or can be user-adjusted between 1.25 ms and 10 s by connecting the CT pin to an external capacitor. The TPS3808 device has a very low typical quiescent current of 2.4 µA, so it is well-suited to battery-powered applications. It is available in the SOT-23 and 2-mm × 2-mm WSON packages, and is fully specified over a temperature range of –40°C to 125°C (TJ).