1°C Temperature Sensor with Beta Compensation
Datasheet
5.1.1
Conversion Rates
The EMC1402 may be configured for different conversion rates based on the system requirements.
The conversion rate is configured as described in Section 6.5. The default conversion rate is 4
conversions per second. Other available conversion rates are shown in Table 6.6.
5.1.2
Dynamic Averaging
Dynamic averaging causes the EMC1402 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 6.4). 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 5.1 for the EMC1402.
Table 5.1 Supply Current vs. Conversion Rate for EMC1402
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
120uA
135uA
165uA
230uA
365uA
625uA
660uA
725uA
730uA
745uA
775uA
100uA
105uA
110uA
115uA
130uA
165uA
225uA
350uA
485uA
745uA
775uA
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
5.2
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).
SMSC EMC1402
Revision 1.16 (03-15-07)
DATA1S7HEET
SMSC [ SMSC CORPORATION ]
