Analog Devices dBCool ADT7473 Manual page 69

Table 38. Register 0x63—Enhance Acoustics Register 2 (Power-On Default = 0x00)
1
Bit Name R/W
[2:0] ACOU3 R/W
[3] EN3 R/W
[6:4] ACOU2 R/W
[7] EN2 R/W
1 This register becomes read-only when the Configuration Register 1
Table 39. PWM Minimum Duty Cycle Registers
Register Address
0x64
0x65
0x66
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.
Table 40. Register 0x64, Register 0x65, and Register 0x66—PWM Minimum Duty Cycle Registers (Power-On Default = 0x80, 50%
duty cycle)
Bit Name
<7:0> PWM duty cycle
1
Table 41. T Registers
MIN
Register Address
0x67
0x68
0x69
1 These are the T registers for each temperature channel. When the temperature measured exceeds T
MIN
with temperature according to T
RANGE
2
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.
Description
These bits select the ramp rate applied to the PWM3 output. Instead of PWM3 jumping instantly to its
newly calculated speed, PWM3 ramps gradually at the rate determined by these bits. This effect enhances
the acoustics of the fan being driven by the PWM3 output.
Time Slot Increase
000 = 1
001 = 2
010 = 3
011 = 5
100 = 8
101 = 12
110 = 24
111 = 48
When this bit is 1, acoustic enhancement is enabled on PWM3 output.
These bits select the ramp rate applied to the PWM2 output. Instead of PWM2 jumping instantly to its
newly calculated speed, PWM2 ramps gradually at the rate determined by these bits. This effect enhances
the acoustics of the fans being driven by the PWM2 output.
Time Slot Increase
000 = 1
001 = 2
010 = 3
011 = 5
100 = 8
101 = 12
110 = 24
When this bit is 1, acoustic enha
lock bi
1
R/W Description
R/W PWM1 minimum duty cycle.
R/W PWM2 minimum duty cycle.
R/W PWM3 minimum duty cycle.
R/W Description
R/W These bits define the PWM
0x00 = 0% duty cycle (fan off ).
0x40 = 25% duty cycle.
0x80 = 50% duty cycle.
0xFF = 100% duty cycle (fan full speed).
2
R/W Description
R/W Remote 1 temperature T
R/W Local temperature T
R/W Remote 2 temperature T
.
Time for 33% to 100%
35 sec
17.6 sec
11.8 sec
7 sec
4.4 sec
3 sec
1.6 sec
0.8 sec
Time for 33% to 100%
35 sec
17.6 sec
11.8 sec
7 sec
4.4 sec
3 sec
1.6 sec
nceme nt is ena bled on PWM2 output.
t is s et to 1. Any further attempts t
duty cycle for PWMx.
MIN
.
MIN
.
MIN
.
MIN
, the appropriate fan runs at minimum speed and increases
MIN
Rev. A | Page 69 of 76
o write to this register have no effect.
Power-On Default
0x80 (50% duty cycle)
0x80 (50% duty cycle)
0x80 (50% duty cycle)
Power-On Default
0x9A (90°C)
0x9A (90°C)
0x9A (90°C)
ADT7473