Kontron COMe Starterkit Eval T2 - Manual (Page 142)

COM Express Interfaces
2.22.8. Fan Connector
Figure 57: Fan Connector Reference Schematic
FAN_TACHIN and FAN_PWMOUT in Figure 57: Fan Connector Reference Schematic above are
COM.0 pins reclaimed from the VCC_12V pool. Q13 / Q14 and U34 / U35 are the necessary
circuitry on the Carrier Board to handle the 12V protection according to chapter 2.22.10
'Protecting COM.0 Pins Reclaimed From the VCC_12V Pool' on page 144 below. This reference
schematic shows a 4-wire fan implementation, which should be preferred over a 3-wire fan. 4-
wire fan implementations allow better sensing and control of the fan.
PICMG ® COM Express ® Carrier Board Design Guide Rev. 2.0 / December 6, 2013
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VC C _12V
VCC_12V
VC C _3V3
VC C _3V3
VC C _3V3
VCC _5V0
VC C _3V3
C E X F A N _ T A C H IN
C E X F A N _ P W M O U T
R 2 4 5
1 k
U 3 5
N C 7 S Z 0 4
2
3
4
5
1
R 2 6 1
1 0 k
J P 1 2
R 2 4 4
4 k 7
R 2 4 9
4 k 7
J 3 8
D 5 3
B Z X 8 4 C 3 V 3
C 2 5 8
1 0 0 n
5 0 V
J 3 7
M o le x 4 7 0 5 3 -1 0 0 0
G N D 1
1 2 V 2
S E N S E 3
C O N T R O L 4
R 2 6 4
1 0 k
R 2 5 9
4 k 7
R 2 5 4
2 k 2 1
Q 1 3
2 N 7 0 0 2
3
1
2
C 2 4 9
1 0 0 n
5 0 V
U 3 4
N C 7 S Z 0 4
2
3
4
5
1
Q 1 4
2 N 7 0 0 2
3
1
2
Fan