600nA ultra-low quiescent current supervisor with programmable delay and manual reset

The TPS3808E family of microprocessor supervisory

circuits monitors system voltages from 0.4V to 5V, 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 TPS3808E device uses a precision reference to

achieve 0.5% threshold accuracy. The reset delay time can be set to 20ms by

disconnecting the CT pin, 300ms by connecting the CT pin to

VDD using a resistor, or can be user-adjusted between 1.25ms and 10s

by connecting the CT pin to an external capacitor. The TPS3808E device

has a very low typical quiescent current of 0.6µA, and is designed for

battery-powered applications. The TPS3808E is available in the SOT-23 (6) , and is

fully specified over a temperature range of –40°C to 125°C (TJ).