Multiple Channel 1°C Temperature Sensors 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, the counter is reset. If a number of consecutive
measurements above the Therm Limit occurs, 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 7.14. 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 7.14. The default setting is 1
consecutive out of limit conversion.
Table 7.14 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])
7.13
Beta Configuration Registers
Table 7.15 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
EMC1413
and 07h
for
External
Diode 2 Beta
Configuration
26h
R/W
-
-
-
-
ENABLE2
EMC1414
These registers are used to set the Beta Compensation factor that is used for the external diode
channels.
Bit 3 - ENABLEX - Enables the Beta Compensation factor auto-detection function. The ENABLE2
control is disabled for the EMC1414; beta compensation cannot be enabled for External Diode 2 or 3.
‘0’ - The Beta Compensation Factor auto-detection circuitry is disabled.
‘1’ - The Beta Compensation factor auto-detection 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. This is the default for
SMSC EMC1413 / EMC1414
Revision 1.41 (02-23-12)
DATA3S7HEET
SMSC [ SMSC CORPORATION ]
