ASC7512 Datasheet, PDF (21/35 Pages) List of Unclassifed Manufacturers – DIGITAL TEMPERATURE SENSOR WITH INTEGRATED FAN CONTROL

aSC7512
Register 5F-60h: Auto Fan Speed Range, PWM Frequency
Register Read/ Register Name Bit 7 Bit 6
Address Write
(MSB)
5Fh
R/W
Zone 1 Range
Fan1 Frequency
RAN3 RAN2
60h
R/W Zone 2 Range
RAN3 RAN2
Bit 5
RAN1
RAN1
Bit 4
RAN0
RAN0
Bit 3
HLFRQ
RES
Bit 2
FRQ2
RES
Bit 1
FRQ1
RES
Bit 0 Default
(LSB) Value
FRQ0
C3
RES
C3
Lock
X
X
In Auto Fan Mode, when the temperature for a zone is above the Temperature Limit (Registers 67-69h) and below its
Absolute Temperature Limit (Registers 6A-6Bh), the speed of a fan assigned to that zone is determined as follows:
When the temperature reaches the Fan Temp Limit for a zone, the PWM output assigned to that zone will be Fan PWM
Minimum. Between Fan Temp Limit and (Fan Temp Limit + Range), the PWM duty cycle will increase linearly according to
the temperature as shown in the figure below. The PWM duty cycle will be 100% at (Fan Temp Limit + Range).
PWM frequency - FRQ[3:0] and HLFRQ
The PWM frequency bits [3:0] determine the PWM frequency for the fan. The aSC7512 has high and low frequency ranges
for the PWM outputs that are controlled by the HLFRQ bit.
PWM Frequency Selection (Default = 0011 = 30.04 Hz).
HLFRQ FRQ [2:0]
PWM
Frequency
0
000
10.01 Hz
0
001
15.02 Hz
0
010
23.14 Hz
0
011
30.04 Hz (Default)
0
100
38.16 Hz
0
101
47.06 Hz
0
110
61.38 Hz
0
111
94.12 Hz
1
000
22.5 kHz
1
001
24 kHz
1
010
25.7 kHz
1
011
25.7 kHz
1
100
27.7 kHz
1
101
27.7 kHz
1
110
30 kHz
1
111
30 kHz
Table 9 Register Setting vs PWM Frequency
© Andigilog, Inc. 2006
RAN[3:0]
0000
0001
0010
0011
0100
0101
0110
0111
1000
1001
Linear Control
Range (°C)
2
2.5
3.33
4
5
6.67
8
10
13.33
16
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August 2006 - 70A05003