1°C Temperature Sensor with Beta Compensation
Datasheet
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 6.14. 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 6.14. The default setting is 1
consecutive out of limit conversion.
Table 6.14 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])
6.13
Beta Configuration Registers
Table 6.15 Beta Configuration Registers
ADDR.
R/W
REGISTER
B7
B6
B5
B4
B3
B2
B1
B0
DEFAULT
External
Diode 1 Beta
Configuration
25h
R/W
-
-
-
-
ENABLE1
BETA1[2:0]
BETA2[2:0]
08h
08h for
External
Diode 2 Beta
Configuration
EMC1403
or 07h for
EMC1404
26h
R/W
-
-
-
-
ENABLE2
This register is used to set the Beta Compensation factor that is used for the external diode channels.
Bit 3 - ENABLEx - Enables the Beta Compensation factor autodetection function. This function shall
be disabled for External Diode 2.
‘0’ - The Beta Compensation Factor autodetection circuitry is disabled. The External Diode will
always use the Beta Compensation factor set by the BETAx[2:0] bits.
‘1’ (default) - The Beta Compensation factor autodetection circuitry is enabled. At the beginning of
every conversion, the optimal Beta Compensation factor setting will be determined and applied.
The BETAx[2:0] bits will be automatically updated to indicate the current setting.
Revision 2.0 (08-10-12)
SMSC EMC1403/EMC1404
DATA3S8HEET
SMSC [ SMSC CORPORATION ]
