Seagate ST3300457SS, 100516226, ST3300657SS, ST3300557SS A Mps, See +12V current profile in Figure

Table 5 300 GB DC power requirements

		NOTES	3 GBIT MODE		6 GBIT MODE
			(AMPS)	(AMPS)	(AMPS)	(AMPS)
Voltage			+5V	+12V [2]	+5V	+12V [2]
Regulation		[5]	±5%	±5% [2]	±5%	±5% [2]
Avg idle current		[1] [7]	0.34	0.58	0.35	0.58
Maximum starting current
(peak DC) DC	3σ	[3]	0.53	1.92	0.54	1.92
(peak AC) AC	3σ	[3]	0.98	3.82	0.86	3.98
Delayed motor start (max) DC	3σ	[1] [4]	0.47	0.04	0.48	0.04
Peak operating current (random read):
Typical DC	[1][6]	[1]	0.41	0.88	0.42	0.90
Maximum DC	3σ	[1]	0.42	0.95	0.43	0.95
Maximum DC (peak)	3σ		1.18	2.78	1.20	2.74
Peak operating current (random write):
Typical DC	[1][6]	[1]	0.48	0.80	0.49	0.81
Maximum DC	3σ	[1]	0.49	0.83	0.51	0.82
Maximum DC (peak)	3σ		1.18	2.68	1.20	2.66
Peak operating current (sequential read):
Typical DC	[1][6]	[1]	0.91	0.59	0.92	0.59
Maximum DC	3σ	[1]	0.93	0.60	0.94	0.61
Maximum DC (peak)	3σ		1.20	0.98	1.24	1.00
Peak operating current (sequential write):
Typical DC	[1][6]	[1]	0.89	0.58	0.90	0.59
Maximum DC	3σ	[1]	0.93	0.60	0.94	0.60
Maximum DC (peak)	3σ		1.22	0.98	1.22	0.96

[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 15,000 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 1.

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

[5]See paragraph 6.2.1, "Conducted noise immunity." Specified voltage tolerance includes ripple, noise, and transient response.

[6]Operating condition is defined as random 8 block reads at 375 I/Os per second for 600GB models, and 380 I/Os per second for 450GB and 300GB models. Current and power specified at nominal voltages.

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

CHEETAH 15K.7 SAS PRODUCT MANUAL, REV. F 20