1°C Multiple Temperature Sensor with Beta Compensation and Hottest of Thermal Zones
Datasheet
Chapter 4 Product Description
The EMC1046/EMC1047 are SMBus temperature sensors. The EMC1046/EMC1047 monitor up to six
(6) external diodes and one internal diode.
Thermal management is performed in cooperation with a host device. This consists of the host reading
the temperature data of both the external and internal temperature diodes of the EMC1046/EMC1047
and using that data to control the speed of one or more fans.
Because the EMC1046/EMC1047 automatically corrects for temperature errors due to series
resistance in temperature diode lines, there is greater flexibility in where external diodes are positioned
and better measurement accuracy than previously available devices without resistance error
correction. As well, the automatic beta detection feature means that there is no need to program the
device according to which type of diode is present. Therefore, the device can power up ready to
operate for any system configuration including those diodes that require the BJT or transistor model.
Figure 4.1 shows a system level block diagram of the EMC1046/EMC1047.
.
EMC1046/7
DP1 / DN6 (1047 only)
CPU
DN1 / DP6 (1047 only)
VDD
DP2 / DN3
Optional
Host
APD
DN2 / DP3
SMDATA
SMCLK
DP4 / DN5
DN4 / DP5
SMBus
Interface
Optional
APD
Internal
Diode
Figure 4.1 System Diagram for EMC1046/EMC1047
4.1
Modes of Operation
The EMC1046/EMC1047 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.
Revision 0.69 (06-29-09)
SMSC EMC1046/EMC1047
DATA1S4HEET
SMSC [ SMSC CORPORATION ]
