RPM-Based Fan Controller with Multiple Temperature Zones & Hardware Thermal Shutdown
Datasheet
PWM Output Drive Frequency
Variation vs. Supply Voltage
FSC Algorithm PWM Ramping
Update Time = 200ms; Max Step = 16 PWM counts
RPM Target from 0 RPM -> 8000 RPM @ time t = 0
1.4
1.2
Base = 2441Hz, Divide =
128 = 19Hz
1
0.8
0.6
0.4
0.2
0
PWM
Output
Base = 26kHz, Divide = 0
10x Zoom
on PWM
Output
2.95
3.05
3.15
3.25
3.35
3.45
3.55
3.65
Spin Up Routine Ends – begins
normal operation
Update Time ends, PWM
duty cycle changed
Supply Voltage (V)
Update Time ends, PWM duty
cycle changed
Duty Cycle Measured
FSC Algorithm Spin Up Routine
FSC Algorithm Spin Up Routine – NoKick
Spin Time = 1.0s; Spin Level = 50%; UpdateTime = 200ms;
RPM Target from 0 RPM -> 8000 RPM @ time t = 0
Spin Time = 1.0s; Spin Level = 55%; Updated Time = 200ms;
RPM Target from 0 RPM -> 8000 RPM @ time t = 0
PWM
Output
PWM
Output
10x Zoom
on PWM
Output
10x Zoom
on PWM
Output
t = 0
Duty Cycle Measured = 53.8%
t = 0
Duty Cycle Measured = 50%
SMSC EMC2113
Revision 1.2 (10-08-09)
DATA7S5HEET
SMSC [ SMSC CORPORATION ]
