EMC2103-2-AP-TR Standard Microsystems (SMSC), EMC2103-2-AP-TR Datasheet - Page 21

• Manufacturer Part Number: EMC2103-2-AP-TR
• Description: CLOSED LOOP RPM FAN CONTROLLER
• Manufacturer: Standard Microsystems (SMSC)

RPM-Based Fan Controller with HW Thermal Shutdown
Datasheet
SMSC EMC2103
5.1
The EMC2103 provides a hardware Critical/Thermal Shutdown function for systems.
block diagram of this Critical/Thermal Shutdown function. The Critical/Thermal Shutdown function
accepts configuration information from the fixed states of the SHDN_SEL pin as described in
Section
Each of the software programmed temperature limits can be optionally configured to act as inputs to
the Critical / Thermal Shutdown independent of the hardware shutdown operation. When configured to
operate this way, the SYS_SHDN# pin will be asserted when the temperature meets or exceeds the
limit. The pin will be released when the temperature drops below the limit however the individual status
bits will not be cleared if set (see
The analog portion of the Critical/Thermal Shutdown function monitors the hardware determined
shutdown channel (see
point. This TRIP_SET point is set by the system designer with a single external resistor divider as
described in
The SYS_SHDN is asserted when the indicated temperature meets or exceeds the temperature
threshold (T
defined by the fault queue. If the HW_SHDN output is asserted and the temperature drops below the
threshold, then it will be set to a logic ‘0’ state.
Critical/Thermal Shutdown
Shutdown Sensor
H/W Thermal
5.1.1.
TRIP_SET
P
Section
Figure 5.2 Block Diagram of Critical / Thermal Shutdown
) established by the TRIP_SET input pin for a number of consecutive measurements
5.1.2.
Temperature
Temperature
Conversion
Conversion
Section
5.1.1). This measured temperature is then compared with TRIP_SET
Section
Critical / Thermal Shutdown
DATASHEET
6.13).
21
SW_SHDN
HW_SHDN
Shutdown Enable
Software
Resistor
Decode
SHDN_SEL
VDD
SYS_SHDN
SMBus
Traffic
Revision 0.88 (06-30-08)
Figure 5.2
is a