MIC2772

Dual Voltage Supervisor

General Description

The MIC2772 is a dual power supply supervisor that

provides under-voltage monitoring and power-on

reset generation.

It may replace two discrete

voltage supervisors such as MIC1810, MIC1815,

MIC809, MIC811, MIC6315, etc.

The two voltage

supervisors

are

completely

independent.

Each

functional block features an under-voltage detector,

a delay-generator, and a de-bounced manual reset

input.

A wide choice of voltage thresholds is available.

The reset output is asserted at power-on and any

time the input voltage drops below the reference

voltage. It remains asserted for the chosen timeout

period after the input rises back above the threshold.

Reset timeouts of 20, 140, and 1100ms (minimum)

are available.

A reset can be generated at any time by asserting

the manual reset input, /MR. This input is internally

de-bounced, and the reset output will remain active

for the timeout period after the release of /MR. The

/MR input can also be used to daisy-chain one or

more of the MIC2772’s supervisors onto existing

power monitoring circuitry or other supervisors.

The tiny 2x2mm MLF package has a footprint

smaller than that of a single SOT23 voltage

supervisor.

Data sheets and support documentation can be

found on Micrel’s web site at www.micrel.com.

Features

• Two independent voltage supervisors

• Directly replaces discrete supervisors

• Generates power-on reset pulses

• De-bounced manual reset Inputs

• Choice of voltage thresholds

• 20, 140, or 1100ms reset timeouts

• Reset output may be pulled above VCC

• Rejects brief input transients

• Ultra-small 2x2mm MLF package

Applications

• Servers

• Embedded Controllers

• Telecommunications Systems

• Power Supply Sequencing

• Hot-swapping

• Power supplies

____________________________________________________________________________________________________

Typical Application

MR1

MR2

GND2

RESET2

VCC2

VCC2

10k

10k

RESET1

VCC1

VCC1

GND1

RESET

VCC

GND

GND

RESET

VCC

µP

µP

MIC2772 Typical Application Circuit

April 2005

M9999-042005

(408) 955-1690