1 Features

• Power-on reset generator with adjustable delay

time: 1.25 ms to 10 s

• Very low quiescent current: 2.4 μA typical

• High threshold accuracy: 0.5% typical

• Fixed threshold voltages for standard voltage rails

from 0.9 V to 5 V and adjustable voltage down to

0.4 V are available

• Manual reset ( MR) input

• Open-drain RESET output

• Temperature range: –40°C to 125°C

• Small SOT-23 and 2-mm × 2-mm WSON

packages

2 Applications

• DSP or microcontroller applications

• Notebook and desktop computers

• PDAs and hand-held products

• Portable and battery-powered products

• FPGA and ASIC applications

3 Description

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 wellsuited

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).