User's Manual

Temperature Sensor Measurement
Variable Speed DC Fan Control using the MC9RS08KA2, Rev. 0
Freescale Semiconductor 21
Table 3-3. Temperature Conversion Table
Temperature
(°C)
Channel Resistance
(kΩ)
(from sensor data sheet)
Voltage
across
Sensor
(V)
Predefined
Motor Speed
(rpm)
Target PWM Period
(Timer Counts
(1)
)
NOTES:
1. The resolution of a timer count is 64µs.
25 or below 10 2.86 1000 232
30 – 34 8.082 2.59 1200 193
35 – 39 6.577 2.34 1400 165
40 – 44 5.387 2.09 1600 144
45 – 49 4.441 1.86 1800 128
50 – 54 3.683 1.65 2000 115
55 – 59 3.024 1.44 2200 105
60 – 64 2.53 1.26 2400 96
65 – 69 2.128 1.11 2600 88
70 – 74 1.799 0.97 2800 82
75 – 79 1.528 0.85 3000 76
80 – 84 1.304 0.74 3200 71
85 – 89 1.118 0.65 3400 67
90 – 94 0.962 0.57 3600 63
95 – 99 0.831 0.50 3800 60
100 or above 0.698 0.43 4000 57