EMC1046 Standard Microsystems Corp., EMC1046 Datasheet - Page 14

• Manufacturer Part Number: EMC1046
• Description: 1 Degree C Multiple Temperature Sensor With Beta Compensation And Hottest Of Thermal Zones
• Manufacturer: Standard Microsystems Corp.

Chapter 4 Product Description
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Revision 0.66 (06-02-08)
4.1
Optional
Optional
APD
APD
CPU
Modes of Operation
The EMC1046/EMC1047are 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
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.
shows a system level block diagram of the EMC1046/EMC1047.
Figure 4.1 System Diagram for EMC1046/EMC1047
DP1 / DN6 (1047 only)
DN1 / DP6 (1047 only)
DP2 / DN3
DN2 / DP3
DP4 / DN5
DN4 / DP5
EMC1046/7
Internal
Diode
1°C Multiple Temperature Sensor with Beta Compensation and Hottest of Thermal Zones
DATASHEET
SMDATA
SMCLK
14
VDD
Interface
SMBus
Host
SMSC EMC1046/EMC1047
Datasheet