General Description

The MAX6746–MAX6753 low-power microprocessor

(µP) supervisory circuits monitor single/dual system

supply voltages from 1.575V to 5V and provide maxi-

mum adjustability for reset and watchdog functions.

supply voltage or RESET IN falls below its reset thresh-

old or when manual reset is pulled low. The reset output

and RESET IN rise above the reset threshold. The reset

function features immunity to power-supply transients.

The MAX6746–MAX6753 have ±2% factory-trimmed

reset threshold voltages in approximately 100mV incre-

ments from 1.575V to 5.0V and/or adjustable reset

threshold voltages using external resistors.

The reset and watchdog delays are adjustable with

external capacitors. The MAX6746–MAX6751 contain a

watchdog select input that extends the watchdog time-

out period by 128x. The MAX6752/MAX6753 contain a

window watchdog timer that looks for activity outside an

expected window of operation.

The MAX6746–MAX6753 are available with a push-pull

or open-drain active-low RESET output. The MAX6746–

MAX6753 are available in an 8-pin SOT23 package and

are fully specified over the automotive temperature

range (-40°C to +125°C).

Applications

Features

o Factory-Set Reset Threshold Options from 1.575V

to 5V in ~100mV Increments

o Adjustable Reset Threshold Options

o Single/Dual Voltage Monitoring

o Capacitor-Adjustable Reset Timeout

o Capacitor-Adjustable Watchdog Timeout

o Min/Max (Windowed) Watchdog Option

o Manual Reset Input Option

o 3.7µA Supply Current

o Push-Pull or Open-Drain RESET Output Options

o Power-Supply Transient Immunity

o Small 8-Pin SOT23 Packages

µP Reset Circuits with Capacitor-Adjustable

Reset/Watchdog Timeout Delay

________________________________________________________________ Maxim Integrated Products

1

WDI

WDS

GND

1

2

8

7

RESET

SWT

SRT

RESET IN (MR)

( ) ARE FOR MAX6746 AND MAX6747 ONLY.

TOP VIEW

3

4

6

5

MAX6746–

MAX6751

SOT23-8

Pin Configurations

19-2530; Rev 2; 8/03

For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct! at

1-888-629-4642, or visit Maxim’s website at www.maxim-ic.com.

Note: “_ _” represents the two number suffix needed when

ordering the reset threshold voltage value for the

MAX6746/MAX6747 and MAX6750–MAX6753. The reset

threshold voltages are available in approximately 100mV incre-

ments. Table 2 contains the suffix and reset factory-trimmed

voltages. All devices are available in tape-and-reel only. There

is a 2500-piece minimum order increment for standard ver-

sions (see Table 3). Sample stock is typically held on standard

versions only. Nonstandard versions require a minimum order

increment of 10,000 pieces. Contact factory for availability.

Medical Equipment

Automotive

Intelligent Instruments

Portable Equipment

Battery-Powered

Computers/Controllers

Embedded Controllers

Critical µP Monitoring

Set-Top Boxes

Computers

Ordering Information

PART

TEMP RANGE

PIN-PACKAGE

MAX6746KA_ _-T

-40°C to +125°C

8 SOT23-8

MAX6747KA_ _-T

-40°C to +125°C

8 SOT23-8

MAX6748KA-T

-40°C to +125°C

8 SOT23-8

MAX6749KA-T

-40°C to +125°C

8 SOT23-8

MAX6750KA_ _-T

-40°C to +125°C

8 SOT23-8

MAX6751KA_ _-T

-40°C to +125°C

8 SOT23-8

MAX6752KA_ _-T

-40°C to +125°C

8 SOT23-8

MAX6753KA_ _-T

-40°C to +125°C

8 SOT23-8

Selector Guide appears at end of data sheet.

Typical Operating Circuit appears at end of data sheet.

Pin Configurations continued at end of data sheet.