General Description

The MAX16033–MAX16040 supervisory circuits reduce

the complexity and number of components required for

power-supply monitoring and battery control functions

in microprocessor (µP) systems. The devices signifi-

cantly improve system reliability and accuracy com-

pared to other ICs or discrete components. The

MAX16033–MAX16040 provide µP reset, backup-bat-

tery switchover, power-fail warning, watchdog, and

chip-enable gating features.

The MAX16033–MAX16040 operate from supply volt-

ages up to 5.5V. The factory-set reset threshold voltage

ranges from 2.32V to 4.63V. The devices feature a man-

ual-reset input (MAX16033/MAX16037), a watchdog

timer input (MAX16034/MAX16038), a battery-on output

(MAX16035/MAX16039), an auxiliary adjustable reset

input (MAX16036/MAX16040), and chip-enable gating

(MAX16033–MAX16036). Each device includes a

power-fail comparator and offers an active-low push-

pull reset or an active-low open-drain reset.

The MAX16033–MAX16040 are available in 2mm x

2mm, 8-pin or 10-pin µDFN packages and are fully

specified from -40°C to +85°C.

Applications

Features

♦ Low 1.2V Operating Supply Voltage

♦ Precision Monitoring of 5.0V, 3.3V, 3.0V, and 2.5V

Power-Supply Voltages

♦ Independent Power-Fail Comparator

♦ Debounced Manual-Reset Input

♦ Watchdog Timer, 1.6s Timeout

♦ Battery-On Output Indicator

♦ Auxiliary User-Adjustable RESETIN

♦ Low 13µA Quiescent Supply Current

♦ Two Available Output Structures:

Active-Low Push-Pull Reset

Active-Low Open-Drain Reset

♦ Active-Low Reset Valid Down to 1.2V

♦ Power-Supply Transient Immunity

♦ 140ms (min) Reset Timeout Period

♦ Small 2mm x 2mm, 8-Pin and 10-Pin µDFN

Packages

Low-Power Battery Backup

Circuits in Small µDFN Packages

________________________________________________________________

Maxim Integrated Products

1

19-0882; Rev 0; 7/07

For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642,

or visit Maxim’s website at www.maxim-ic.com.

Ordering Information continued on last page.

*

These parts offer a choice of reset threshold voltages. From the

Reset Threshold Ranges table, insert the desired threshold volt-

age code in the blank to complete the part number. See Selector

Guide for a listing of device features.

+

Denotes a lead-free package.

T

= Tape and reel.

Pin Configurations and Typical Operating Circuit appear at

end of data sheet.

Ordering Information

PART*

TEMP RANGE

PIN-

PACKAGE

PKG

CODE

MAX16033LLB_ _+T

-40°C to +85°C 10 µDFN-10 L1022-1

MAX16033PLB_ _+T

-40°C to +85°C 10 µDFN-10 L1022-1

MAX16034LLB_ _+T

-40°C to +85°C 10 µDFN-10 L1022-1

MAX16034PLB_ _+T

-40°C to +85°C 10 µDFN-10 L1022-1

Note: Replace “_” with L for push-pull or P for open-drain RESET and PFO outputs.

Selector Guide

PART

MR

WATCHDOG

BATTON

RESETIN

CEIN/CEOU

PFI,

PFO

PIN-PACKAGE

MAX16033_

✓✓

✓

10 µDFN-10

MAX16034_

✓✓

✓

10 µDFN-10

MAX16035_

✓✓

✓

10 µDFN-10

MAX16036_

✓✓

✓

10 µDFN-10

MAX16037_

✓

✓

8 µDFN-8

MAX16038_

✓✓

8 µDFN-8

MAX16039_

✓✓

8 µDFN-8

MAX16040_

✓✓

8 µDFN-8

Portable/Battery-

Powered Equipment

POS Equipment

Critical µP/µC Power

Monitoring

Set-Top Boxes

Controllers

Computers

Fax Machines

Industrial Control

Real-Time Clocks

Intelligent Instrument