Multiple Channel 1°C Temperature Sensor with Beta Compensation
Datasheet
6.1.2
Dynamic Averaging
Dynamic averaging causes the EMC1412 to measure the external diode channels for an extended time
based on the selected conversion rate. This functionality can be disabled for increased power savings
at the lower conversion rates (see Section 7.4, "Configuration Register"). When dynamic averaging is
enabled, the device will automatically adjust the sampling and measurement time for the external diode
channels. This allows the device to average 2x or 16x longer than the normal 11 bit operation
(nominally 21ms per channel) while still maintaining the selected conversion rate. The benefits of
dynamic averaging are improved noise rejection due to the longer integration time as well as less
random variation of the temperature measurement.
When enabled, the dynamic averaging applies when a one-shot command is issued. The device will
perform the desired averaging during the one-shot operation according to the selected conversion rate.
When enabled, the dynamic averaging will affect the average supply current based on the chosen
conversion rate as shown in Table 6.1.
Table 6.1 Supply Current vs. Conversion Rate for EMC1412
AVERAGING FACTOR (BASED ON
AVERAGE SUPPLY CURRENT
11-BIT OPERATION)
ENABLED
(DEFAULT)
ENABLED
(DEFAULT)
CONVERSION RATE
DISABLED
DISABLED
1 / 16 sec
1 / 8 sec
1 / 4 sec
1 / 2 sec
1 / sec
660uA
660uA
660uA
660uA
660uA
930uA
950uA
1010uA
1020uA
1050uA
1100uA
430uA
430uA
430uA
430uA
430uA
475uA
510uA
630uA
775uA
1050uA
1100uA
16x
16x
16x
16x
16x
16x
8x
1x
1x
1x
1x
1x
2 / sec
1x
4 / sec (default)
8 / sec
1x
4x
1x
16 / sec
2x
1x
32 / sec
1x
1x
64 / sec
0.5x
0.5x
6.2
THERM Output
The THERM output is asserted independently of the ALERT output and cannot be masked. Whenever
any of the measured temperatures exceed the user programmed Therm Limit values for the
programmed number of consecutive measurements, the THERM output is asserted. Once it has been
asserted, it will remain asserted until all measured temperatures drop below the Therm Limit minus
the Therm Hysteresis (also programmable).
When the THERM pin is asserted, the THERM status bits will likewise be set. Reading these bits will
not clear them until the THERM pin is deasserted. Once the THERM pin is deasserted, the THERM
status bits will be automatically cleared.
SMSC EMC1412
Revision 1.41 (02-23-12)
DATA1S9HEET
SMSC [ SMSC CORPORATION ]
