Table 7. spike smoothing, 17 registers 64-66h: minimum pwm duty cycle, Functional description – Rainbow Electronics LM85 User Manual
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Functional Description
(Continued)
TABLE 7. Spike Smoothing
ZN-X[2:0]
Spike Smoothed Over
000
35 seconds
001
17.6 seconds
010
11.8 seconds
011
7.0 seconds
100
4.4 seconds
101
3.0 seconds
110
1.6 seconds
111
.8 seconds
TABLE 8. PWM Output Below Limit Depending on Value of Off/Min
Off/Min
PWM Action
0
At 0% duty below LIMIT
1
At Min PWM Duty below LIMIT
4.17 Registers 64-66h: Minimum PWM Duty Cycle
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?
64h
R/W
Fan1 PWM Minimum
7
6
5
4
3
2
1
0
80h
U
65h
R/W
Fan2 PWM Minimum
7
6
5
4
3
2
1
0
80h
U
66h
R/W
Fan3 PWM Minimum
7
6
5
4
3
2
1
0
80h
U
These registers specify the minimum duty cycle that the PWM will output when the measured temperature reaches the
Temperature LIMIT register setting.
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.
20035307
FIGURE 2. What LM85 Auto Fan Control Sees With and Without Spike Smoothing
LM85
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