THMC50 Datasheet, PDF (18/32 Pages) Texas Instruments – REMOTE/LOCAL TEMPERATURE MONITOR AND FAN CONTROLLER WITH SMBus INTERFACE

THMC50
REMOTE/LOCAL TEMPERATURE MONITOR AND
FAN CONTROLLER WITH SMBus INTERFACE
SLIS090 – JULY 1999
PRINCIPLES OF OPERATION
temperature measurement system (continued)
Remote
Die
VCC3AUX
10 µA
90 µA
Remote
Temperature
Sensor
(CPU)
REMOTE_DIODE+
THMC50
Front End
REMOTE_DIODE–
Substrate
Analog
MUX
Low-Pass
Filter
8-Bit A/D
Converter
Substrate
On-Chip Temperature
Sensor
Control
State
Machine
GND
Figure 14. THMC50 Temperature-to-Digital Converter Analog Front-End Block Diagram
temperature interrupts
There are two value RAM limits for the temperature reading that affect the interrupt behavior of the THMC50.
They are remote thermal diode high limit and remote thermal diode low limit.
temperature interrupt operation
Exceeding any of the value RAM thermal limits results in the INT output being asserted (if the corresponding
mask bits are not set) and respective status bit to be set. The INT output remains asserted until cleared by either
reading the interrupt status register, or setting the INT clear (bit 2) of the configuration register. Status bits are
cleared by reading the interrupt status register. The INT output can only be asserted again if the appropriate
high limit is reprogrammed. If the high limit is not reprogrammed, then the INT output is asserted again once
the temperature falls below the appropriate low limit. The INT output is now asserted again if the temperature
again rises above the appropriate high limit or falls below the appropriate low limit. See Figure 15 for an example.
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