Seagate ST34571N/W/WC/WD/DC, ST32171N/W/WC/WD/DC manual DC power requirements Amps ST32171/ST32271

Barracuda 4LP Installation Guide, Rev. B						15
Table 2b. DC power requirements (Amps)
			ST32171/ST32271
			N/W/WC		WD/DC
			Single-ended		Differential
Voltage			+5V	+12V	+5V	+12V
Regulation [5]			±5%	±5%[2]	±5%	±5%[2]
Max. operating current
DC3σ [1]			0.81	0.85	1.21	0.85
		[1]	0.46	0.52	0.70	0.52
Avg. idle current DCX
Max. starting current
(peak DC) DC3σ [3]			0.78	2.00	1.1	2.00
(peak AC) AC3σ [3]				3.1		3.1
Delayed motor start (max)
DC3σ [1][4]			0.50	0.20	0.90	0.20
Peak operating current
	[1][6]		0.72	0.73	0.91	0.73
Typical DCX
Maximum DC3σ [1]			0.81	0.85	1.21	0.85
Maximum (peak) 3σ			1.5	2.3	2.0	2.3

[1]Measured with an average reading DC ammeter. Instanta- neous +12V current peaks will exceed these values.

[2]A –10% droop is permissible during initial start of the spindle but must return to ±5% before reaching 7,200 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 the +12V current profile in the Barracuda 4LP Product Manual (publication number 77767491).

[4]This condition occurs when the Motor Start option is enabled and the drive has not yet received a Start Motor command.