Seagate ST3400755SS manual Electrical description, Pin descriptions, SAS pin descriptions

9.4.4Electrical description

SAS drives use the device connector for:

•DC power

•SAS interface

•Activity LED

This connector is designed to either plug directly into a backpanel or accept cables.

9.4.5Pin descriptions

This section provides a pin-out of the SAS device and a description of the functions provided by the pins.

Table 10: SAS pin descriptions

Pin	Signal name	Signal type
S1	Port A Ground
S2*	+Port A_in	Diff. input pair
S3*	-Port A_in
S4	Port A Ground
S5*	-Port A_out	Diff output pair
S6*	+Port A_out
S7	Port A Ground
S8	Port B Ground
S9*	+Port B_in	Diff. input pair
S10*	-Port B_in
S11	Port A Ground
S12*	-Port B_out	Diff output pair
S13*	+Port B_out
S14	Port B Ground

*- Short pin to support hot plugging NC - No connection in the drive.

Pin	Signal name	Signal type
P1*	NC (reserved 3.3Volts)
P2*	NC (reserved 3.3Volts)
P3	NC (reserved 3.3Volts)
P4	Ground
P5	Ground
P6	Ground
P7	5 Volts charge
P8*	5 Volts
P9*	5 Volts
P10	Ground
P11*	Ready LED	Open collector out
P12	Ground
P13	12 Volts charge
P14*	12 Volts
P15*	12 Volts

54 Cheetah NS SAS Product Manual, Rev. B