Seagate ST973352SS, ST973452SS, ST973252SS, ST9146752SS manual 73GB models DC power requirements

Table 3:	73GB models DC power requirements
				3.0 Gbit mode		6.0 Gbit mode
			Notes	(Amps)	(Amps)	(Amps)	(Amps)
Voltage				+5V	+12V [2]	+5V	+12V [2]
Regulation			[5]	±5%	±5% [2]	±5%	±5% [2]
Avg idle current DC			[1] [7]	0.36	0.18	0.37	0.18
Maximum starting current
(peak DC) DC		3σ	[3]	0.51	1.09	0.51	1.08
(peak AC) AC		3σ	[3]	0.93	1.73	0.99	1.86
Delayed motor start (max) DC		3σ	[1] [4]	0.56	0.06	0.57	0.05
Peak operating current: (random read)
Typical DC			[1] [6]	0.45	0.36	0.46	0.36
Maximum DC		3σ	[1]	0.47	0.37	0.48	0.37
Maximum (peak) DC		3σ		1.16	1.16	1.14	1.16
Peak operating current: (random write)
Typical DC			[1]	0.52	0.28	0.53	0.28
Maximum DC		3σ	[1]	0.55	0.28	0.56	0.28
Maximum (peak) DC		3σ		1.14	1.18	1.16	1.20
Peak operating current: (sequential read)
Typical DC			[1]	0.88	0.18	0.89	0.18
Maximum DC		3σ	[1]	0.92	0.19	0.93	0.19
Maximum (peak) DC		3σ		1.18	0.40	1.20	0.42
Peak operating current: (sequential write)
Typical DC			[1]	0.88	0.18	0.89	0.18
Maximum DC		3σ	[1]	0.94	0.19	0.95	0.19
Maximum (peak) DC		3σ		1.16	0.40	1.18	0.40

[1]Measured with average reading DC ammeter. Instantaneous +12V current peaks will exceed these val- ues. 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 15k 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 1.

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

[5]See paragraph 7.2.1, "Conducted noise immunity." Specified voltage tolerance includes ripple, noise, and transient response.

[6]Operating condition is defined as random 8 block reads.

[7]During idle, the drive heads are relocated every 60 seconds to a random location within the band from three-quarters to maximum track.

Savvio 15K.2 SAS Product Manual, Rev. E 23