RPM-Based Fan Controller with HW Thermal Shutdown
Datasheet
Bit 0 - POLARITY1 - Determines the polarity of PWM1 (if enabled).
‘0’ (default) - the Polarity of the PWM driver is normal. A drive setting of 00h will cause the output
to be set at 0% duty cycle and a drive setting of FFh will cause the output to be set at 100% duty
cycle.
‘1’ - The Polarity of the PWM driver is inverted. A drive setting of 00h will cause the output to be
set at 100% duty cycle and a drive setting of FFh will cause the output to be set at 0% duty cycle.
6.18
PWM Base Frequency Register
Table 6.24 PWM Base Frequency Register
ADDR
R/W
REGISTER
B7
B6
B5
B4
B3
B2
B1
B0
DEFAULT
PWM Base
Frequency
PWM_BASE[1:0
]
2Bh
R/W
-
-
-
-
-
-
03h
The PWM Base Frequency Register controls base frequency of the PWM output.
Bits 1-0 - PWM_BASE[1:0] - Determines the base frequency of the PWM driver (PWM).
Table 6.25 PWM_BASEx[1:0] it Decode
PWM_BASE[1:0]
1
0
BASE FREQUENCY
0
0
1
1
0
1
0
1
26.00kHz
19.531kHz
4,882Hz
2,441Hz (default)
6.19
Limit Registers
Table 6.26 Limit Registers
ADDR
R/W
REGISTER
B7
B6
B5
B4
B3
B2
B1
B0
DEFAULT
External Diode
1 High Limit
55h
(+85°C)
30h
R/W
Sign
64
32
16
8
4
2
1
External Diode
2 High Limit **
55h
(+85°C)
31h **
32h **
34h
R/W
R/W
R/W
R/W
Sign
Sign
Sign
Sign
64
64
64
64
32
32
32
32
16
16
16
16
8
8
8
8
4
4
4
4
2
2
2
2
1
1
1
1
External Diode
3 High Limit **
55h
(+85°C)
Internal Diode
High Limit
55h
(+85°C)
External Diode
1 Low Limit
00h
(0°C)
38h
SMSC EMC2103
Revision 0.85 (01-29-08)
DATA5S3HEET
SMSC [ SMSC CORPORATION ]
