General Description

The MAX6642 precise, two-channel digital temperature

sensor accurately measures the temperature of its own

die and a remote PN junction and reports the tempera-

ture data over a 2-wire serial interface. The remote PN

junction is typically a substrate PNP transistor on the

die of a CPU, ASIC, GPU, or FPGA. The remote PN

junction can also be a discrete diode-connected small-

signal transistor.

The 2-wire serial interface accepts standard system

management bus (SMBus™), Write Byte, Read Byte,

Send Byte, and Receive Byte commands to read the

temperature data and to program the alarm thresholds.

To enhance system reliability, the MAX6642 includes an

SMBus timeout. The temperature data format is 10 bit

with the least significant bit (LSB) corresponding to

+0.25°C. The ALERT output asserts when the local or

remote overtemperature thresholds are violated. A fault

queue may be used to prevent the ALERT output from

setting until two consecutive faults have been detected.

Measurements can be done autonomously or in a sin-

gle-shot mode.

Remote accuracy is ±1°C maximum error between

+60°C and +100°C. The MAX6642 operates from -40°C

to +125°C, and measures remote temperatures

between 0°C and +150°C. The MAX6642 is available in

a 6-pin TDFN package with an exposed pad.

Applications

Desktop Computers

Notebook Computers

Servers

Thin Clients

Test and Measurement

Workstations

Graphic Cards

Features

o Dual Channel: Measures Remote and Local

Temperature

o +0.25°C Resolution

o High Accuracy ±1°C (max) (Remote) and

±2°C (Local) from +60°C to +100°C

o Measures Remote Temperature Up to +150°C

o Programmable Overtemperature Alarm

Temperature Thresholds

o Tiny TDFN Package with Exposed Pad

±1°C, SMBus-Compatible Remote/Local

Temperature Sensor with Overtemperature Alarm

________________________________________________________________

Maxim Integrated Products

1

Ordering Information

19-2920; Rev 3; 10/09

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.

EVALUATION

KIT

AVAILABLE

PART

TEMP RANGE

PIN-PACKAGE

MAX6642ATT90-T

-40°C to +125°C

6 TDFN-EP*

MAX6642ATT92-T

-40°C to +125°C

6 TDFN-EP*

MAX6642ATT94-T

-40°C to +125°C

6 TDFN-EP*

MAX6642ATT96-T

-40°C to +125°C

6 TDFN-EP*

MAX6642ATT98-T

-40°C to +125°C

6 TDFN-EP*

MAX6642ATT9A-T

-40°C to +125°C

6 TDFN-EP*

MAX6642ATT9C-T

-40°C to +125°C

6 TDFN-EP*

MAX6642ATT9E-T

-40°C to +125°C

6 TDFN-EP*

MAX6642

2200pF

0.1

μF

μP

DXP

GND

SDA

SCLK

ALERT

DATA

CLOCK

INTERRUPT TO

μP

47

Ω

10k

Ω EACH

3.3V

Typical Operating Circuit

PART

MEASURED TEMP RANGE

TOP

MARK

MAX6642ATT90-T

0°C to +150°C

AFC

MAX6642ATT92-T

0°C to +150°C

AFD

MAX6642ATT94-T

0°C to +150°C

AFE

MAX6642ATT96-T

0°C to +150°C

AFF

MAX6642ATT98-T

0°C to +150°C

AEW

MAX6642ATT9A-T

0°C to +150°C

AFG

MAX6642ATT9C-T

0°C to +150°C

AFH

MAX6642ATT9E-T

0°C to +150°C

AFI

Selector Guide

T = Tape and reel.

*

EP = Exposed pad.

Pin Configuration and Functional Diagram appear at end of

data sheet.

SMBus is a trademark of Intel Corp.