emc2104 Standard Microsystems Corp., emc2104 Datasheet - Page 27

• Manufacturer Part Number: emc2104
• Description: Emc2104 Dual Rpm-based Pwm Fan Controller With Hardware Thermal Shutdown
• Manufacturer: Standard Microsystems Corp.

Dual RPM-Based PWM Fan Controller with Hardware Thermal Shutdown
Datasheet
SMSC EMC2104
T4 - Hyst
T3 - Hyst
T2 - Hyst
T5 - Hyst
T6 - Hyst
T8 - Hyst
T7 - Hyst
Temp
T5
T6
T4
T3
T2
T1
T8
T7
to control the fan drive output independently (or jointly) by programming up to eight pairs of
temperature and drive setting entries.
The user programs the look-up table based on the desired operation. If the RPM based Fan Speed
Control Algorithm is to be used (see
temperature setting of interest. Alternately, if the RPM based Fan Speed Control Algorithm is not to be
used, then the user must program a drive setting for each temperature setting of interest.
If the measured temperature on the External Diode channel meets or exceeds any of the temperature
thresholds for any of the temperature columns (see
set to the desired setting corresponding to the exceeded temperature. In cases where multiple
temperature channel thresholds are exceeded, the highest fan drive setting will take precedence.
When the measured temperature drops to a point below a lower threshold minus the hysteresis value,
the fan output will be set to the corresponding lower set point.
Figure 5.3
channel.
See
Appendix B
Temperature
shows an example of this operation using temperature - drive setting pairs for a single
Averaged
for examples of the Look Up Table operation.
Figure 5.3 Fan Control Look-Up Table Example
Setting
Fan
Measurement taken
DATASHEET
Section
27
Time
5.5), then the user must program an RPM target for each
Appendix
B), the fan output will be automatically
Revision 1.74 (05-08-08)
Setting
S6
S4
S3
S2
S1
S8
S7
S5
Fan