General Description

The MAX6329/MAX6349 are low-dropout, micropower

linear voltage regulators with integrated microproces-

sor reset circuits. Each is available with preset +3.3V,

+2.5V, +1.8V, or adjustable output voltages and can

deliver up to 150mA load current. Employing internal P-

channel MOSFET pass transistors, the devices con-

sume only 25µA supply current, independent of the

device load. The low supply current, low dropout volt-

age, and integrated reset functionality make these

devices ideal for battery powered portable equipment.

The MAX6329/MAX6349 include an internal reset circuit

that indicates when the regulator output drops below

standard microprocessor supply tolerances (-5% or

-10%). The reset output remains asserted for 100ms

(min) after the regulator output exceeds the selected

reset threshold, ensuring that supply voltages and clock

oscillators have stabilized before processor activity is

enabled. Reset outputs are available in push-pull (active-

low or -high) and open-drain (active-low) options. The

internal reset circuit replaces external microprocessor

supervisors or RC-based reset time delays.

The MAX6329/MAX6349 are optimized for use with a

1µF (min) output capacitor. The regulator output volt-

age is adjustable with an external resistor-divider net-

work at SET (reset threshold voltages track the desired

output voltage). Each device includes thermal shut-

down protection, output short-circuit protection, and

reverse leakage protection. The MAX6329 includes a

shutdown feature to reduce regulator current below

1µA (max) and the MAX6349 offers a manual reset

input to assert a microprocessor reset while the regula-

tor output is within specification.

________________________Applications

Hand-Held Instruments

Electronic Planners

Palm Top Computers

PCMCIA Cards

USB Devices

Cellular Telephones

Cordless Telephones

Modems

Features

o Preset +3.3V/+2.5V/+1.8V or Adjustable Regulator

Output

o ±3.0% Regulator Accuracy Over the Specifed

Operating Range

o 25µA Supply Current

o Low 180mV Dropout at 100mA Load

o Small Output Capacitor (1µF min ceramic or

tantalum)

o Zero Reverse Leakage Current

o Thermal and Short-Circuit Protection

o Integrated Microprocessor Reset Circuit with

100ms (min) Timeout

o Open-Drain and Push-Pull Reset Outputs

o Regulator Shutdown Input (MAX6329) or Manual

Reset Input (MAX6349)

o 6-Pin SOT23 Package

150mA, SOT23, Low-Dropout Linear Regulators

with Internal Microprocessor Reset Circuit

________________________________________________________________ Maxim Integrated Products

1

GND

RESET/RESET

16

OUT

5

SET

IN

MAX6329/

MAX6349

SOT23-6

TOP VIEW

2

34

(MR) SHDN

( ) ARE FOR MAX6349 ONLY.

Pin Configuration

19-1889; Rev 2; 4/01

Ordering Information

PART

TEMP. RANGE

PIN-

PACKAGE

MAX6329_ _ UT-T

0°C to +85°C

6 SOT23-6

MAX6349_ _ UT-T

0°C to +85°C

6 SOT23-6

These parts offer a choice of regulator/reset voltages and reset

outputs. From the Selector Guide, insert the desired suffix let-

ters into the blanks to complete the part number. Each device

is available in nine standard versions. Sample stock is general-

ly held on standard versions only (see Standard Versions

table). Standard versions have an order increment requirement

of 2500 pieces. Nonstandard versions have an order increment

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

nonstandard versions.

Typical Operating Circuit appears at end of data sheet.

Selector Guide appears at end of data sheet.

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.