Seagate ST3146855FC ユーザーズマニュアル

66

Cheetah 15K.5 FC Product Manual, Rev. D

*Short pins in mating backpanel connector.

[1]

This pin may be connected to external logic to detect the presence of the drive. The drive connects this 
pin to the common ground.

[2]

Pins 9, 10, 17, 18, and 39 are option select pins and are tied high by the drive circuitry. The preferred elec-
trical connection at the backplane is either open or grounded (open for the ‘1’ setting, grounded for the ‘0’ 
setting). Alternatively, these pins may be driven by a 3.3V logic device, pulled up to 3.3V through a pull-up 
resistor (recommended size of 10k ohm), or grounded through some other means.

A typical FC-AL differential copper transmitter and receiver pair is shown in Figure 17. The receiver is required 
to provide the AC coupling to eliminate ground shift noise. 

1*

-EN bypass port A

Low Voltage TTL output

21

12 Volts charge

2*

12 Volts

22

Ground

3*

12 Volts

23

Ground

4*

12 Volts

24*

+Port A_in

FC Diff. input pair

5*

-Parallel ESI

25*

-Port A_in

6*

Ground

26

Ground

7*

Active LED out

Open collector out

27*

+Port B_in

FC Diff. input pair

8*

Reserved

28*

-Port B_in

9*

Start_1

[2]

TTL input

29

Ground

10*

Start_2

[2]

TTL input

30*

+Port A_out

FC Diff. output pair

11*

-EN bypass port B

Low Voltage TTL output

31*

-Port A_out

12*

SEL_6

TTL input/output

32

Ground

13*

SEL_5

TTL input/output

33*

+Port B_out

FC Diff. output pair

14*

SEL_4

TTL input

34*

-Port B_out

15*

SEL_3

TTL input/output

35

Ground

16*

Fault LED out

Open collector out

36

SEL_2

TTL input/output

17*

DEV_CTRL_CODE_2

[2]

TTL input

37

SEL_1

TTL input/output

18*

DEV_CTRL_CODE_1

[2]

TTL input

38

SEL_0

TTL input/output

19*

5 Volts

39

DEV_CTRL_CODE_0

TTL input

20*

5 Volts

40

5 Volts charge

TY

.01

Differential

Transfer Medium

.01

Transmitter

TX

RY

Receiver

RX

100

100