EMC2104 Datasheet, PDF (30/101 Pages) SMSC Corporation – Dual RPM-Based PWM Fan Controller with Hardware Thermal Shutdown

Dual RPM-Based PWM Fan Controller with Hardware Thermal Shutdown
Datasheet
Set TACH Target
Count
Measure Fan Speed
Spin Up
Yes
Required
?
No
Perform Spin Up
Routine
Yes
Maintain Fan Drive
Yes
TACH
Reading =
TACH
Target?
No
TACH
Reading <
No
TACH
Target?
Ramp Rate Control
Reduce Fan Drive
Increase Fan Drive
Figure 5.4 RPM based Fan Speed Control Algorithm
Revision 1.74 (05-08-08)
30
DATASHEET
SMSC EMC2104