W83627THF Nuvoton Technology Corporation of America, W83627THF Datasheet - Page 37

• Manufacturer Part Number: W83627THF
• Manufacturer: Nuvoton Technology Corporation of America

Specifications of W83627THF

• Pin Count: 128
• Lead Free Status / RoHS Status: Not Compliant

One more protection is provided that DC FAN output voltage will not be decreased to 0 in the above
(3) situation in order to keep the fans running with a minimum speed. By setting CR[12h] bit3-5 to 1,
FAN output voltage will be decreased to the “ Stop Value ” which are defined at CR[08h],CR[09h] and
CR[15h].
5.5.2
There are 3 pairs of FANIN/FANOUT control at this mode: SYSFANIN with SYSFANOUT, CPUFANIN
with CPUFANOUT, AUXFANIN with AUXFANOUT. At this mode, W83627THF provides the Smart
Fan system which can control the fan speed automatically depend on current fan speeds to keep it
with in a specific range. A wanted fan speed count and interval must be set (ex. 160 ± 10 ) by BIOS.
As long as the fan speed count is the specific range, output voltage will keep the current value. If
current fan speed count is higher than the high limit (ex. 160+10), output voltage will be increased to
keep the count less than the high limit. Otherwise, if current fan speed is less than the low limit(ex.
160-10), output voltage will be decreased to keep the count higher than the low limit. See Figure 5-11
example.
Target Temperature
Fan Speed Cruise mode
Tolerance
Tolerance
DC
Output
Voltage
Count
170
160
150
DC
Output
Voltage
2.5
5
0
58`C
55`C
52`C
2.5
5
A
0
Fan Start = 1.875V
A
Figure 5-10
Figure 5-11
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C
W83627THF/W83627THG
Fan Stop = 1.25V
B
C
Fan Start = 1.875V
D