Multiple Channel 1°C Temperature Sensors with Beta Compensation
Datasheet
CPU / GPU
DP1
Thermal
Junction
DN1
VDD
VDD = 3.3V
3.3V – 5V
Host
SMCLK
EMC1413
SMDATA
ALERT
SMBus
Interface
DP2
THERM / ADDR
DN2
GND
Power Control
Figure 6.2 System Diagram for EMC1413
6.1
Modes of Operation
The EMC1413 and EMC1414 have two modes of operation.
Active (Run) - In this mode of operation, the ADC is converting on all temperature channels at the
programmed conversion rate. The temperature data is updated at the end of every conversion and
the limits are checked. In Active mode, writing to the one-shot register will do nothing.
Standby (Stop) - In this mode of operation, the majority of circuitry is powered down to reduce
supply current. The temperature data is not updated and the limits are not checked. In this mode
of operation, the SMBus is fully active and the part will return requested data. Writing to the one-
shot register will enable the device to update all temperature channels. Once all the channels are
updated, the device will return to the Standby mode.
6.1.1
Conversion Rates
The EMC1413 / EMC1414 may be configured for different conversion rates based on the system
requirements. The conversion rate is configured as described in
The default conversion
rate is 4 conversions per second. Other available conversion rates are shown in
6.1.2
Dynamic Averaging
Dynamic averaging causes the EMC1413 / EMC1414 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
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
.
SMSC EMC1413 / EMC1414
19
Revision 1.41 (02-23-12)
DATASHEET
SMSC [ SMSC CORPORATION ]
