Analog Devices ADT7473 Manual page 65

Table 32. TEMP T /PWM Frequency Registers
RANGE
Register Address
0x5F
0x60
0x61
Bit Name
<2:0> FREQ
Register Address
<3> HF/LF
<7:4> RANGE
1
These registers become read-only when the Configuration Register 1 lock bit is set. Any further attempts to write to these registers have no effect.
1
R/W Description
Read/write Remote 1 T
Read/write Local temperature T
Read/write Remote 2 T
R/W Description
Read/write These bits control the PWMx frequency.
000 = 11.0 Hz.
001 = 14.7 Hz.
010 = 22.1 Hz.
011 = 29.4 Hz.
1
R/W Description
100 = 35.3 Hz (default).
101 = 44.1 Hz.
110 = 58.8 Hz.
111 = 88.2 Hz.
Read/write HF/LF =1, enables high frequency PWM output for 4 wire fans. Once enabled, 3-wire
fan specific settings have no effect (that is, pulse stretching).
0x5F, HF/LF = 1 enables high frequency mode for Fan 1.
0x60, HF/LF = 1 enables high frequency mode for Fan 2.
0x61, HF/LF = 1 enables high frequency mode for Fan 3.
Read/write These bits determine the PWM duty cycle vs. the temperature slope for automatic fan
control.
0000 = 2°C.
0001 = 2.5°C.
0010 = 3.33°C.
0011 = 4°C.
0100 = 5°C.
0101 = 6.67°C.
0110 = 8°C.
0111 = 10°C.
1000 = 13.33°C.
1001 = 16°C.
1010 = 20°C.
1011 = 26.67°C.
1100 = 32°C (default).
1101 = 40°C.
1110 = 53.33°C.
1111 = 80°C
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/PWM1 frequency.
RANGE
/PWM2 frequency.
RANGE
/PWM3 frequency.
RANGE
ADT7473
Power-On Default
0xCC
0xCC
0xCC