EMC2101-R-ACZL-TR datasheet(23/57 Pages) SMSC

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SMBus Fan Control with 1°C Accurate Temperature Monitoring

Datasheet

SMSC EMC2101

Revision 2.54 (06-16-09)

DATASHEET

Figure 5.3 shows a block diagram of the temperature measurement circuit. As shown, the EMC2101

incorporates a delta-sigma analog to digital converter that integrates the temperature diode voltage

from multiple bias currents.

The external temperature diodes can be connected as shown in Figure 5.4.

5.5.1

Temperature Measurement Results and Data

The results of the internal and external temperature measurements are stored in the internal and

external temperature registers respectively. These are then compared with the values stored in the

High Limit Registers. The internal temperature measurements are stored in 8-bit format while the

external temperature measurements are stored in 11-bit format.

Figure 5.3 Block Diagram of Temperature Monitoring Circuit

Figure 5.4 External Diode configurations

CPU

substrate

PNP

ILOW

IHIGH

Resistance

Error

Correction

Input

Filter &

Sampler

ADC

ΔΣ

Local Ground

Typical remote

substrate transistor

i.e. CPU substrate PNP

Typical remote

discrete PNP transistor

i.e. 2N3906

Typical remote

discrete NPN transistor

i.e. 2N3904

EMC2101-R-ACZL-TR Datasheet(PDF) 23 Page - SMSC Corporation