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Rainbow Electronics MAX6869 User Manual

General description, Applications, Features

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General Description

The MAX6854–MAX6869 ultra-low-current (170nA, typ)
microprocessor (µP) supervisory circuits combine volt-
age 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 asserted, or the watchdog timer expires.
The reset output remains asserted for a minimum timeout
period after V

CC

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 Threshold
Suffix Guide
). Each device is offered with six minimum
reset timeout options, ranging from 10ms to 1200ms.

The MAX6854–MAX6869 are offered in a variety of con-
figurations (see Selector Guide). The MAX6854–
MAX6856 and MAX6861–MAX6869 provide a manual
reset input, MR. The MAX6864–MAX6869 offer a watch-
dog timer that monitors activity at the WDI input for code
execution errors. The MAX6864–MAX6869 offer watch-
dog timeout options of 3.3s or 209s (typ). The
MAX6861–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

6 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)

Immune to Short V

CC

Transients

Guaranteed Reset Valid to V

CC

= +1.1V

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–TPS3838

(MAX6861/MAX6862/MAX6863)

MAX6854–MAX6869

Nanopower µP Supervisory Circuits with

Optional Manual Reset, Watchdog Timer

________________________________________________________________

Maxim Integrated Products

1

Ordering Information

PART

TEMP RANGE

PIN-PACKAGE

MAX6854

UK_ _D_-T*

-40°C to +85°C

5 SOT23-5

MAX6855

UK_ _D_-T*

-40°C to +85°C

5 SOT23-5

19-3139; Rev 0; 2/04

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 on last page.

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.

*Future product—Contact factory for availability.

Pin Configurations appear at the end of data sheet.

Selector Guide appears at the end of data sheet.

Typical Operating Circuit

MAX6864
MAX6867

µP

V

CC

V

CC

GND

GND

MANUAL

RESET

RESET

I/O

V

CC

0.1µF

RESET

MR

WDI