UIC811L-X-AE3-R datasheet(7/8 Pages) UTC

7 / 8 page

UIC811

CMOS IC

UNISONICTECHNOLOGIESCO.,LTD

7 of 8

www.unisonic.com.tw

QW-R502-317.H

TYPICAL APPLICATION CIRCUIT

UTC

UIC811

VCC

RESET

µP

VCC

RESET

VCC

APPLICATION INFORMATION

Microprocessor Reset

As soon as VCC falls below the reset threshold voltage, the RESET pin is asserted. But the RESET pin can

keep asserted for a period of 140ms after VCC rose above the reset threshold voltage. After a power failure the reset

operation can keep the processor being reset and powers up properly.

VCC Transients

The UTC UIC811 series won’t cause a reset typically as this situation: a negative-going transient 125mV below

the reset threshold with a duration of 20µs or less.

Interfacing to Bidirectional Reset Pins

Connecting a 4.7kΩ resistor in series with the UTC UIC811 series output and the µP reset pin can make the

UTC UIC811 series interface with µPs with bidirectional reset pins.

RESET Valid at Low Voltage

As the figure below, adding a resistor which is recommended 100kΩ can ensure the RESET output remains

low with VCC down to 0V. The size of the resistor should be not too large which will load the output excessively and

not too small which can pull-down any stray leakage currents.

UIC811L-X-AE3-R Datasheet(PDF) 7 Page - Unisonic Technologies