EMC1822 datasheet(21/103 Pages) MICROCHIP

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SYS_SHDN Pull Up Decode

ALERT Pull-Up Decode

Combine

d Decode

(HEX)

Threshold

Temperatur

2Ch

111°C

2Dh

112°C

The Hardware Shutdown circuitry measures the External Diode 1 Channel and compares it against the

Hardware Thermal Shutdown Limit. The THERM pin consecutive alert counter (default 4 for the

SYS_SHDN pin) applies to this comparison. If the temperature meets or exceeds the limit for the number

of consecutive measurements, the SYS_SHDN pin is asserted. The SYS_SHDN pin remains asserted

until the temperature drops below the limit minus 10°C. As well, all of the measurement channels

(including the External Diode 1 channel) can be configured to assert theSYS_SHDN pin. If a channel is

configured to assert the SYS_SHDN pin, the temperature on the measured channel must exceed the

programmed therm limit value. This is treated in the same way as the THERM output. For additional

information, see 8.11.17 HARDWARE THERMAL SHUTDOWN LIMIT.

7.7

External Diode Connections

The EMC1822 can be configured to measure a CPU substrate transistor, a discrete 2N3904 thermal

diode, or an CPU/GPU processor diode. The diodes can be connected as indicated in the figure below.

The EMC1823 can be configured to measure a CPU substrate transistor, a discrete 2N3904 thermal

diode, or an CPU/GPU processor diode on the External Diode 1 or External Diode 2 channels. For the

EMC1824, External Diode 2 and External Diode 3 channels are configured to measure a pair of discrete

anti-parallel diodes (shared on pins DP2 and DN2). The supported configurations for the external diode

channels are shown in the following figure.

Multi-Channel Low Voltage Temp Sens...

System Block Diagram

Datasheet

DS20006048A-page 21

EMC1822 датащи(PDF) 21 Page - Microchip Technology