1°C Dual SMBus Sensor with Resistance Error Correction
Datasheet
The ALERT/THERM2 pin de-asserts when the EMC1002 responds to an alert response address
(ARA=0001 100) sent by the host if the out of limit condition no longer exists, but it does not reset if
the error condition remains. The ALERT/THERM2 pin can be masked so that it will not assert in the
event of an out of limit temperature measurement.
Logic
Temp
Level
Temperature High Limit
SMBus ARA
Temperature Low Limit
Logic High
ALERT/THERM2
Time
Figure 4.3 ALERT/THERM2 Response to Temperature Limits Exceeded
The ALERT/THERM2 pin can be configured as a second THERM pin that asserts when the temperature
measurement exceeds the Temperature High Limit value. In this mode, the output will not de-assert
until the temperature drops below the Temperature High Limit minus the THERM Hysteresis value.
4.6
ADDR/THERM Output
The ADDR/THERM output asserts if the temperature measurement exceeds the programmable THERM
limit. It can be used to drive a fan or other fail-safe devices. The ADDR/THERM pin is open drain and
requires a pull-up resistor to VDD. For the EMC1002-2, the value of this pull-up resistor determines the
slave address per Table 1.2 on page 3. The ADDR/THERM pin cannot be masked.
When the ADDR/THERM pin is asserted, it will not de-assert until the temperature drops below the
THERM limit minus the THERM hysteresis value.
Logic
Temp
Level
THERM
Hysteresis
THERM Limit
THERM Limit - THERM Hysterisis
Hysteresis
Logic High
THERM
Time
Figure 4.4 ADDR/THERM Output Response to Temperature Limit Exceeded
Revision 1.1 (12-02-04)
SMSC EMC1002
PRELIMINAR1Y2 DATASHEET
SMSC [ SMSC CORPORATION ]
