MAX6648_08 Datasheet, PDF (1/16 Pages) Maxim Integrated Products – Precision SMBus-Compatible Remote/Local Temperature Sensors with Overtemperature Alarms

19-2545; Rev 4; 6/08
Precision SMBus-Compatible Remote/Local
Temperature Sensors with Overtemperature Alarms
General Description
The MAX6648/MAX6692 are precise, two-channel digi-
tal temperature sensors. They accurately measure the
temperature of their own die and a remote PN junction,
and report the temperature in digital form using a 2-wire
serial interface. The remote PN junction is typically the
emitter-base junction of a common-collector PNP on a
CPU, FPGA, or ASIC.
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 MAX6648/MAX6692
include an SMBus timeout. A fault queue prevents the
ALERT and OVERT outputs from setting until a fault has
been detected one, two, or three consecutive times
(programmable).
The MAX6648/MAX6692 provide two system alarms:
ALERT and OVERT. ALERT asserts when any of four tem-
perature conditions are violated: local overtemperature,
remote overtemperature, local undertemperature, or
remote undertemperature. OVERT asserts when the tem-
perature rises above the value in either of the two OVERT
limit registers. The OVERT output can be used to activate
a cooling fan, or to trigger a system shutdown.
Measurements can be done autonomously, with the
conversion rate programmed by the user, or in a single-
shot mode. The adjustable conversion rate allows the
user to optimize supply current and temperature
update rate to match system needs.
Remote accuracy is ±0.8°C maximum error between
+25°C and +125°C with no calibration needed. The
MAX6648/MAX6692 operate from -55°C to +125°C, and
measure temperatures between 0°C and +125°C. The
MAX6648 is available in an 8-pin µMAX^® package, and the
MAX6692 is available in 8-pin µMAX and SO packages.
Applications
Desktop Computers
Notebook Computers
Servers
Thin Clients
Workstations
Test and Measurement
Multichip Modules
Features
o Dual Channel Measures Remote and Local
Temperature
o +0.125°C Resolution
o High Accuracy ±0.8°C (max) from +25°C to +125°C
(Remote), and ±2°C (max) from +60°C to +100°C
(Local)
o Two Alarm Outputs: ALERT and OVERT
o Two Default OVERT Thresholds Available
MAX6648: +110°C
MAX6692: +85°C
o Programmable Conversion Rate
o SMBus-Compatible Interface
o SMBus Timeout
o Programmable Under/Overtemperature Alarm
Thresholds
o Compatible with 90nm, 65nm, and 45nm Process
Technology
Ordering Information
PART
MAX6648MUA
MAX6648YMUA
MAX6692MUA
MAX6692MSA
MAX6692YMUA
MAX6692YMSA
PIN-
PACKAGE
8 µMAX
8 µMAX
8 µMAX
8 SO
8 µMAX
8 SO
MEASURED
TEMP RANGE
0°C to +125°C
0°C to +125°C
0°C to +125°C
0°C to +125°C
0°C to +125°C
0°C to +125°C
Note: All devices operate over the -55°C to +125°C temperature
range.
Typical Operating Circuit
0.1μF
3.3V
200Ω
V_CC
DXP
SDA
MAX6648 _SCLK
MAX6692
DXN
ALERT
2200pF
OVERT
μP
GND
10kΩ EACH
DATA
CLOCK
INTERRUPTED TO μP
TO FAN DRIVER OR
SYSTEM SHUTDOWN
SMBus is a trademark of Intel Corp.
µMAX is a registered trademark of Maxim Integrated Products, Inc.
Pin Configuration and Functional Diagram appear at end of
data sheet.
________________________________________________________________ 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.