EMC6D103-CK SMSC [SMSC Corporation], EMC6D103-CK Datasheet - Page 68

• Manufacturer Part Number: EMC6D103-CK
• Description: FAN CONTROL DEVICE WITH HIGH FREQUENCY PWM
• Manufacturer: SMSC [SMSC Corporation]

Revision 0.4 (04-04-05)
Example for PWM1 assigned to Zone 1:
■
■
■
In this case, the PWM1 duty cycle will be 50% at 50°C.
Since (Zone 1 Low Temp Limit) + (Zone 1 Range) = 50°C + 8°C = 58°C, the fan controlled by PWM1
will run at 100% duty cycle when the temperature of the Zone 1 sensor is at 58°C.
Since the midpoint of the fan control range is 54°C, and the median duty cycle is 75% (Halfway
between the PWM Minimum and 100%), PWM1 duty cycle would be 75% at 54°C.
Above (Zone 1 Low Temp Limit) + (Zone 1 Range), the duty cycle must be 100%.
The PWM frequency bits [3:0] determine the PWM frequency for the fan.
PWM Frequency Selection (Default =0011=29.3Hz)
Range Selection (Default =1100=32°C)
Zone 1 Low Temp Limit (Register 67h) is set to 50°C (32h).
Zone 1 Range (Register 5Fh) is set to 8°C (7h)
PWM1 Minimum Duty Cycle (Register 64h) is set to 50% (80h)
Table 8.29 Register Setting vs. Temperature Range
Table 8.28 Register Setting vs. PWM Frequency
1000 - 1001
1011 - 1111
FREQ[3:0]
RAN[3:0]
0000
0001
0010
0011
0100
0101
0110
1010
0000
0001
0010
0011
0100
0101
0110
0111
Fan Control Device with High Frequency PWM Support and Hardware Monitoring Features
DATASHEET
68
PWM FREQUENCY
29.3 Hz (default)
RANGE (°C)
~25 Khz
11.0 Hz
14.6 Hz
21.9 Hz
35.2 Hz
44.0 Hz
58.6 Hz
87.7 Hz
3.33
6.67
N/A
N/A
2.5
2
4
5
8
SMSC EMC6D103
Datasheet