Seagate ST3400755SS manual Physical/electrical specifications, AC power requirements

6.0Physical/electrical specifications

This section provides information relating to the physical and electrical characteristics of the drive.

6.1AC power requirements

None.

6.2DC power requirements

The voltage and current requirements for a single drive are shown below. Values indicated apply at the drive connector.

Table 2: ST3400755SS DC power requirements

			ST3400755SS		ST3400755SS
			1.5 Gbit mode		3 Gbit mode
		Notes	(Amps)	(Amps)	(Amps)	(Amps)
Voltage			+5V	+12V [2]	+5V	+12V [2]
Regulation		[5]	±5%	±5% [2]	±5%	±5% [2]
		[1] [6]	0.76	0.37	0.75	0.37
Avg idle current DCX
Maximum starting current
(peak DC) DC	3σ	[3]	0.89	1.73	0.88	1.73
(peak AC) AC	3σ	[3]	1.10	3.43	1.14	3.40
	3σ
Delayed motor start (max) DC		[1] [4]	0.63	0.04	0.67	0.04
Peak operating current:
		[1]	0.75	0.69	0.78	0.68
Typical DCX
Maximum DC	3σ	[1]	0.78	0.74	0.81	0.74
Maximum (peak) DC	3σ		1.38	2.64	1.40	2.58

[1]Measured with average reading DC ammeter or equivalent sampling scope. Instantaneous +12V current peaks will exceed these values. Power supply at nominal voltage. N (number of drives tested) = 6, 35 Degrees C ambient.

[2]For +12 V, a –10% tolerance is allowed during initial spindle start but must return to ±5% before reaching 10,000 RPM. The ±5% must be maintained after the drive signifies that its power-up sequence has been completed and that the drive is able to accept selection by the host initiator.

[3]See +12V current profile in Figure 19.

[4]This condition occurs after OOB and Speed Negotiation completes but before the drive has received the Notify Spinup primitive.

Cheetah NS SAS Product Manual, Rev. B 23