©

1999 IMP, Inc.

408-432-9100/www.impweb.com

1

Key Features

Applications

N Computers and controllers

N CTI applications

N Embedded controllers

N Battery operated systems

N Intelligent instruments

N Wireless communication systems

N PDAs and handheld equipment

N Lower power, pin compatible replacements for

Maxim MAX706P/R/S/T, MAX708R/S/T

– 30% lower supply current:140µA vs. 200µA

N Precision power supply monitor

– 2.63V threshold (IMP706P/R, IMP708R)

– 2.93V threshold (IMP706S, IMP708S)

– 3.08V threshold (IMP706T, IMP708T)

– New 4.00V threshold (IMP706J, IMP708J)

N Debounced manual reset input

N Auxiliary voltage monitor comparator

– 1.25V threshold

– Battery monitor/auxiliary supply monitor

N Watchdog timer (IMP706P/R/S/T/J)

– Watchdog can be disabled by floating WDI

N 200ms reset time delay

N Three reset signal options

– Active HIGH: IMP706P

– Active LOW: IMP706R/S/T/J

– Active HIGH & LOW outputs: IMP708R/S/T/J

N DIP, SO and MicroSO packages

Block Diagrams

IMP706P/R/S/T/J, IMP708R/S/T/J

IMP706P/R/S/T/J, IMP708R/S/T/J

3/3.3/4.0V

cuits

– Lo

ent

– W

hdog timer

– Br

ection

The IMP706P/R/S/T/J and IMP708R/S/T/J CMOS supervisor circuits

monitor power-supply and battery voltage level, and

µP/µC operation.

A reset is generated when the supply drops below 2.63V (IMP706P/R,

IMP708R), 2.93V (IMP706S, IMP708S), 3.08V (IMP706T, IMP708T) or 4.00

(IMP706J, IMP708J).

The family offers several functional options. Each device generates a

reset signal during power-up, power-down and during brownout

conditions.

In addition, the IMP706P/R/S/T/J feature a 1.6 second watchdog timer.

The watchdog timer output will trigger a reset if connected to MR.

Unlike competitive devices, floating the WDI input pin disables the

watchdog timer.

The IMP708R/S/T/J have both active-HIGH and active-LOW reset out-

puts but no watchdog function. The IMP706P has the same pin-out and

functions as the IMP706R but has an active-HIGH reset output.

A versatile power-fail circuit, useful in checking battery levels and

non-5V supplies, has a 1.25V threshold. All devices have a manual

reset input.

All devices are available in 8-pin DIP, SO and the compact MicroSO

packages. The MicroSO package requires 50% less PC board area than

the conventional SO package.

RESET

RESET

V

CC

RESET

Generator

2.63V (IMP708R)

2.93V (IMP708S)

3.08V (IMP708T)

4.00V (IMP708J)

+

–

+

MR

IMP708R/S/T/J

PFO

GND

1.25V

–

+

PFI

706P_02.eps

20k

Ω

1.25V

–

+

MR

WDI

IMP706P/R/S/T/J

WDO

RESET

(RESET) IMP706P

PFO

GND

V

CC

20k

Ω

RESET

Generator

2.63V (IMP706P/R)

2.93V (IMP706S)

3.08V (IMP706T)

4.00V (IMP706J)

+

–

+

PFI

Timebase

Watchdog

Timer

Transition

Detector

706P_01.eps