TABLE 9. PWM Duty vs Register Setting

Current Duty

Value (Decimal)

Value (Hex)

0%

0

00h

0.3922%

1

01h

.

.

.

.

.

.

.

.

.

25.098%

64

40h

.

.

.

.

.

.

.

.

.

50.196%

128

80h

.

.

.

.

.

.

.

.

.

100%

255

FFh

4.18 Registers 67-69h: Temperature Limit

Register

Address

Read/

Write

Register

Name

Bit 7

(MSB)

Bit 6

Bit 5

Bit 4

Bit 3

Bit 2

Bit 1

Bit 0

(LSB)

Default

Value

Lock?

67h

R/W

Zone1 Fan Temp Limit

7

6

5

43210

5Ah

U

68h

R/W

Zone2 Fan Temp Limit

7

6

5

43210

5Ah

U

69h

R/W

Zone3 Fan Temp Limit

7

6

5

43210

5Ah

U

These are the temperature limits for the individual zones. When the current temperature equals this limit, the fan will be turned

on if it is not already. When the temperature exceeds this limit, the fan speed will be increased according to the algorithm set forth

in the Auto Fan Range, PWM Frequency register description. Default = 90˚C = 5Ah

This register becomes Read Only when the Ready/Lock/Start/Override register Lock bit is set. Any further attempts to write to this

register shall have no effect. After power up the default value is used whenever the Ready/Lock/Start/Override register Start bit

is cleared even though modifications to this register are possible.

TABLE 10. Temperature Limit vs Register Setting

Temperature

Reading (Decimal)

Reading (Hex)

−127˚C

−127

81h

.

.

.

.

.

.

.

.

.

−50˚C

−50

CEh

.

.

.

.

.

.

.

.

.

0˚C

0

00h

.

.

.

.

.

.

.

.

.

50˚C

50

32h

.

.

.

.

.

.

.

.

.

127˚C

127

7Fh

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