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ADM±032
FEATURES
GENERAL DESCRIPTION
On-chip and remote temperature sensing
Offset registers for system calibration
0.125°C resolution/1°C accuracy on remote channel
1°C resolution/3°C accuracy on local channel
Fast (up to 64 measurements per second)
2-wire SMBus serial interface
Supports SMBus alert
Programmable under/overtemperature limits
Programmable fault queue
The ADM10321 is a dual-channel digital thermometer and
under/overtemperature alarm intended for use in PCs and
thermal management systems. The device can measure the
temperature of a remote thermal diode, which can be located
on the processor die or can be a discrete device (2N3904/06),
accurate to 1°C. A novel measurement technique cancels out
the absolute value of the transistor’s base emitter voltage so that
no calibration is required. The ADM1032 also measures its
ambient temperature.
Overtemperature fail-safe THERM output
Programmable THERM limits
The ADM1032 communicates over a 2-wire serial interface
compatible with system management bus (SMBus) standards.
Under/overtemperature limits can be programmed into the
Programmable THERM hysteresis
170 μA operating current
5.5 μA standby current
3 V to 5.5 V supply
Small 8-lead SOIC and MSOP packages
device over the SMBus, and an
output signals when the
ALERT
on-chip or remote temperature measurement is out of range.
This output can be used as an interrupt or as a SMBus alert. The
output is a comparator output that allows CPU clock
THERM
throttling or on/off control of a cooling fan. An ADM1032-1 and
ADM1032-2 are available. The difference between the
ADM1032 and theADM1032-1 is the default value of the
APPLICATIONS
Desktop and notebook computers
Smart batteries
Industrial controllers
Telecommunications equipment
Instrumentation
external
limit. The ADM1032-2 has a different
THERM
SMBus address. The SMBus address of theADM1032-2 is 0x4D.
1 Patents 5,982,221; 6,097,239; 6,133,753; 6,169,442; 5,867,012.
Embedded systems
FUNCTIONAL BLOCK DIAGRAM
ADDRESS POINTER
REGISTER
CONVERSION RATE
REGISTER
ON-CHIP
TEMPERATURE
SENSOR
LOCAL TEMPERATURE
LOW LIMIT REGISTER
LOCAL TEMPERATURE
VALUE REGISTER
LOCAL TEMPERATURE
HIGH LIMIT REGISTER
D+
D–
ANALOG
MUX
A/D
LIMIT
COMPARATOR
CONVERTER
REMOTE TEMPERATURE
LOW LIMIT REGISTER
BUSY
RUN/STANDBY
REMOTE TEMPERATURE
HIGH LIMIT REGISTER
REMOTE TEMPERATURE
VALUE REGISTER
LOCAL THERM LIMIT
REGISTER
REMOTE OFFSET
REGISTER
EXTERNAL THERM LIMIT
REGISTER
CONFIGURATION
REGISTER
EXTERNAL DIODE OPEN-CIRCUIT
INTERRUPT
MASKING
ALERT
THERM
STATUS REGISTER
ADM1032
SMBUS INTERFACE
V
GND
SDATA
SCLK
DD
Figure 1.
Rev. E
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