1°C Temperature Sensor with Beta Compensation
Datasheet
1. Internal Diode reads 71°C and the external diode reads 69°C. Consecutive alert counter for INT is
incremented to 1.
2. Both the Internal Diode and the External Diode read 71°C. Consecutive alert counter for INT is
incremented to 2and for EXT is set to 1.
3. The External Diode reads 71°C and the Internal Diode reads 69°C. Consecutive alert counter for
INT is cleared and EXT is incremented to 2.
4. The Internal Diode reads 71°C and the external diode reads 71°C. Consecutive alert counter for
INT is set to 1 and EXT is incremented to 3.
5. The Internal Diode reads 71°C and the external diode reads 71°C. Consecutive alert counter for
INT is incremented to 2 and EXT is incremented to 4. The appropriate status bits are set for EXT
and the ALERT pin is asserted. EXT counter is reset to 0 and all other counters hold the last value
until the next temperature measurement.
Bit 7 - TIMEOUT - Determines whether the SMBus Timeout function is enabled.
‘0’ (default) - The SMBus Timeout feature is disabled. The SMCLK line can be held low indefinitely
without the device resetting its SMBus protocol.
‘1’ - The SMBus Timeout feature is enabled. If the SMCLK line is held low for more than 30ms,
then the device will reset the SMBus protocol.
Bits 6-4 - CTHRM[2:0] - Determines the number of consecutive measurements that must exceed the
corresponding THERM Limit before the THERM pin is asserted. All temperature channels use this
value to set the respective counters. The consecutive THERM counter is incremented whenever any
measurement exceed the corresponding THERM Limit.
If the temperature drops below the THERM limit, then the counter is reset. If a number of consecutive
measurements above the THERM limit occurs, then the THERM pin is asserted low.
Once the THERM pin has been asserted, the consecutive therm counter will not reset until the
corresponding temperature drops below the THERM Limit minus the THERM Hysteresis value.
The bits are decoded as shown in Table 6.13. The default setting is 4 consecutive out of limit
conversions.
Bits 3-1 - CALRT[2:0] - Determine the number of consecutive measurements that must have an out of
limit condition or diode fault before the ALERT pin is asserted. All temperature channels use this value
to set the respective counters. The bits are decoded as shown in Table 6.13. The default setting is 1
consecutive out of limit conversion.
Table 6.13 Consecutive Alert / THERM Settings
NUMBER OF CONSECUTIVE OUT OF LIMIT
2
1
0
MEASUREMENTS
1
0
0
0
(default for CALRT[2:0])
0
0
0
1
1
1
2
3
4
1
1
1
(default for CTHRM[2:0])
Revision 1.16 (03-15-07)
SMSC EMC1402
DATA3S2HEET
SMSC [ SMSC CORPORATION ]
