General Description
The MAX6657/MAX6658/MAX6659 are precise, two-
channel digital temperature sensors. Each accurately
measures the temperature of its own die and one
remote PN junction, and reports the temperature in digi-
tal form on a 2-wire serial interface. The remote junction
can be a diode-connected transistor like the low-cost
NPN type 2N3904 or 2N3906 PNP type. The remote
junction can also be a common-collector PNP, such as
a substrate PNP of a microprocessor.
The 2-wire serial interface accepts standard System
Management Bus (SMBus™) commands such as Write
Byte, Read Byte, Send Byte, and Receive Byte to read
the temperature data and program the alarm thresholds
and conversion rate. The MAX6657/MAX6658/
MAX6659 can function autonomously with a program-
mable conversion rate, which allows the control of sup-
ply current and temperature update rate to match
system needs. For conversion rates of 4Hz or less, the
temperature is represented in extended mode as 10
bits + sign with a resolution of 0.125°C. When the con-
version rate is faster than 4Hz, output data is 7 bits +
sign with a resolution of 1°C. The MAX6657/
MAX6658/MAX6659 also include an SMBus timeout
feature to enhance system reliability.
Remote accuracy is ±1°C between +60°C and +100°C
with no calibration needed. The MAX6657 measures
temperatures from 0°C to +125°C and the MAX6658/
MAX6659 from -55°C to +125°C. The MAX6659 has the
added benefit of being able to select one of three
addresses through an address pin, and a second over-
temperature alarm pin for greater system reliability.
Applications
Desktop Computers Workstations
Notebook Computers
Servers
Features
o Dual Channel Measures Remote and Local
Temperature
o 11-Bit, +0.125°C Resolution
o High Accuracy ±1°C (max) from +60°C to +100°C
(Remote)
o No Calibration Required
o Programmable Under/Overtemperature Alarms
o Programmable Conversion Rate
(0.0625Hz to 16Hz)
o SMBus/I
2
C-Compatible Interface
o Two Alarm Outputs: ALERT and OVERT1
(MAX6657 and MAX6658)
o Three Alarm Outputs: ALERT, OVERT1,
and OVERT2 (MAX6659)
o Compatible with 65nm Process Technology
(Y Versions)
MAX6657/MAX6658/MAX6659
±1°C, SMBus-Compatible Remote/Local Temperature
Sensors with Overtemperature Alarms
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Maxim Integrated Products
1
19-2034; Rev 5; 10/10
Ordering Information