General Description

The MAX6854/MAX6855/MAX6856/MAX6858/MAX6860–

MAX6869 ultra-low-current (170nA, typ) microprocessor

(µP) supervisory circuits combine voltage monitoring,

watchdog timer, and manual reset input functions in a 5-

pin SOT23 package. These devices assert a reset signal

whenever the monitored voltage drops below the factory-

trimmed reset threshold voltage, manual reset is assert-

ed, or the watchdog timer expires. The reset output

rises above the reset threshold and manual reset is

deasserted. Factory-trimmed reset threshold voltages

are offered from +1.575V to +4.625V in approximately

100mV increments (see the Threshold Suffix Guide).

Each device is offered with six minimum reset timeout

options, ranging from 10ms to 1200ms.

The MAX6854/MAX6855/MAX6856/MAX6858/MAX6860–

MAX6869 are offered in a variety of configurations (see

the Selector Guide). The MAX6854/MAX6855/MAX6856/

MAX6861–MAX6869 provide a manual reset input, MR.

The MAX6864–MAX6869 offer a watchdog timer that

monitors activity at the WDI input to prevent code execu-

tion errors. The MAX6864–MAX6869 offer watchdog

timeout options of 3.3s or 209s (typ). The MAX6861/

MAX6862/MAX6863 feature a pin-selectable reset delay

period of 10ms or 150ms (min). Push-pull active-low,

push-pull active-high, and open-drain active-low reset

outputs are available.

Applications

Portable/Battery-Powered Equipment

PDAs/Cell Phones

MP3 Players/Pagers

Glucose Monitors/Patient Monitors

Features

♦ Ultra-Low 170nA (typ) Supply Current

♦ Reset Thresholds from +1.575V to +4.625V in

Approximately 100mV Increments

♦ Six Minimum Reset Timeout Period Options from

10ms to 1200ms

♦ Manual Reset Option

♦ Watchdog Timer Option

♦ Pin-Selectable 10ms/150ms (min) Reset Timeout

Period (MAX6861/MAX6862/MAX6863)

♦ Three Reset Output Options:

Push-Pull

RESET

Push-Pull RESET

Open-Drain

RESET

♦ No External Components

♦ Small 5-Pin SOT23 Package

♦ Pin Compatible to the TPS3836/TPS3837/TPS3838

(MAX6861/MAX6862/MAX6863)

Nanopower µP Supervisory Circuits with

Manual Reset and Watchdog Timer

________________________________________________________________ Maxim Integrated Products

1

Ordering Information

PART†

TEMP RANGE

PIN-PACKAGE

MAX6854UK_ _D_-T

-40°C to +85°C

5 SOT23-5

MAX6855UK_ _D_-T

-40°C to +85°C

5 SOT23-5

19-3139; Rev 4; 12/05

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.

Ordering Information continued at end of data sheet.

†Insert reset threshold suffix (see Table 2, Threshold Suffix

Guide) after UK. Insert the number corresponding to the

desired reset timeout period (see Table 4, Reset Timeout

Period) after D.

Note: Sample stock is generally held on standard versions

only (see Table 5, Standard Versions Table). Standard versions

have an order increment of 2500 pieces. Nonstandard versions

have an order increment of 10,000 pieces. Contact factory for

availability of nonstandard versions.

Devices are available in both leaded and lead-free packaging.

Specify lead-free by replacing “-T” with “+T” when ordering.

Pin Configurations and Selector Guide appear at end of

data sheet.

Typical Operating Circuit

MAX6864

MAX6867

µP

GND

GND

MANUAL

RESET

RESET

I/O

0.1

µF

RESET

MR

WDI