x

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________________General Description

The MAX1661/MAX1662/MAX1663 serial-to-parallel/

parallel-to-serial converters are intended to control external

power MOSFETs in power-plane switching applications.

These small, low-cost devices can be used on a system

motherboard to control point-of-load switching from a 2-

wire SMBus™ serial interface. Each device has three high-

voltage open-drain outputs that double as TTL-level logic

inputs, giving them bidirectional capabilities. The I/O pins

can withstand +28V, so they can control battery voltage-

distribution switches in notebook computers.

The MAX1661 is intended for driving N-channel MOSFETs

and its outputs are low upon power-up. The MAX1662/

MAX1663 are intended for P-channel MOSFETs, and their

outputs are high-impedance upon power-up. This ensures

that the MOSFETs are off at power-up, so the system can

enforce power-plane sequencing.

The SMBSUS control input selects control data between

two separate data registers. This feature allows the system

to select between two different power-plane configurations

asynchronously, eliminating latencies introduced by the

serial bus. Other features include thermal-overload and

overcurrent protection, ultra-low supply current, and both

hardware and software interrupt capabilities. These

devices are available in the space-saving 10-pin µMAX

package.

________________________Applications

Power-Plane Switching

Point-of-Load Power-Bus Switching

Notebook and Subnotebook Computers

Desktop Computers

Smart Batteries

____________________________Features

o Performs Serial-to-Parallel and Parallel-to-Serial

Conversions

o Three General-Purpose Digital Input/Output Pins

(withstand +28V)

o SMBus 2-Wire Serial Interface

o Supports SMBSUS Asynchronous Suspend Mode

o 3µA Supply Current

o +2.7V to +5.5V Supply Range

o Space-Saving, Low-Cost 10-Pin µMAX Package

________________________________________________________________

Maxim Integrated Products

1

1

2

3

4

5

10

9

8

7

6

ALERT

SMBCLK

SMBDATA

SMBSUS

I/O3

I/O2

I/O1

MAX1661

MAX1662

MAX1663

µMAX

TOP VIEW

ADD

GND

__________________Pin Configuration

19-1306; Rev 0; 10/97

PART

MAX1661EUB

MAX1662EUB

MAX1663EUB

-40°C to +85°C

-40°C to +85°C

-40°C to +85°C

TEMP. RANGE

PIN-PACKAGE

10 µMAX

10 µMAX

10 µMAX

EVALUATION KIT

AVAILABLE

______________Ordering Information

Typical Operating Circuits appear at end of data sheet.

SMBus is a trademark of Intel Corp.

PART

POWER-ON-

RESET STATE

INTENDED

APPLICATION

SMBus ADDRESS

ADDRESS PIN

ADDRESS

MAX1661

Outputs Low

N-Channel MOSFETs

GND

High-Z

0100000

0111100

1001000

MAX1662

Outputs High

(high-Z state)

P-Channel MOSFETs

GND

High-Z

0100001

0111101

1001001

MAX1663

Outputs High

(high-Z state)

P-Channel MOSFETs

GND

High-Z

0100010

0111110

1001010

______________________________________________________________Selector Guide

Serial-to-Parallel/Parallel-to-Serial Converters and

Load-Switch Controllers with SMBus Interface