19-2920; Rev 3; 10/09
KIT
ATION
EVALU
BLE
AVAILA
±1°C, SMBus-Compatible Remote/Local
Temperature Sensor with Overtemperature Alarm
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.
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
SMBus/I
2
C-Compatible Interface
o
Tiny TDFN Package with Exposed Pad
MAX6642
Ordering Information
PART
MAX6642ATT90-T
MAX6642ATT92-T
MAX6642ATT94-T
MAX6642ATT96-T
MAX6642ATT98-T
MAX6642ATT9A-T
MAX6642ATT9C-T
MAX6642ATT9E-T
TEMP RANGE
-40°C to +125°C
-40°C to +125°C
-40°C to +125°C
-40°C to +125°C
-40°C to +125°C
-40°C to +125°C
-40°C to +125°C
-40°C to +125°C
PIN-PACKAGE
6 TDFN-EP*
6 TDFN-EP*
6 TDFN-EP*
6 TDFN-EP*
6 TDFN-EP*
6 TDFN-EP*
6 TDFN-EP*
6 TDFN-EP*
Applications
Desktop Computers
Notebook Computers
Servers
Thin Clients
Test and Measurement
Workstations
Graphic Cards
T = Tape and reel.
*EP
= Exposed pad.
Pin Configuration and Functional Diagram appear at end of
data sheet.
Typical Operating Circuit
3.3V
0.1μF
47Ω
Selector Guide
PART
MAX6642ATT90-T
MAX6642ATT92-T
MAX6642ATT94-T
MAX6642ATT96-T
MAX6642ATT98-T
MAX6642ATT9A-T
MAX6642ATT9C-T
MEASURED TEMP RANGE
0°C to +150°C
0°C to +150°C
0°C to +150°C
0°C to +150°C
0°C to +150°C
0°C to +150°C
0°C to +150°C
TOP
MARK
AFC
AFD
AFE
AFF
AEW
AFG
AFH
AFI
μP
2200pF
V
CC
10kΩ EACH
DXP
MAX6642
SDA
DATA
CLOCK
INTERRUPT TO
μP
SCLK
ALERT
GND
MAX6642ATT9E-T
0°C to +150°C
SMBus is a trademark of Intel Corp.
________________________________________________________________
Maxim Integrated Products
1
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.
MAXIM [ MAXIM INTEGRATED PRODUCTS ]
