Seagate ST373453LC manual DC power requirements for ST3146855FC model Gbit Amps

Table 3:	DC power requirements for ST3146855FC model
				1 Gbit		2 Gbit		4 Gbit
			Notes	(Amps)	(Amps)	(Amps)	(Amps)	(Amps)	(Amps)
Voltage				+5V	+12V [2]	+5V	+12V [2]	+5V	+12V [2]
Regulation			[5]	±5%	±5% [2]	±5%	±5% [2]	±5%	±5% [2]
			[1] [7]	0.77	0.54	0.79	0.53	0.84	0.53
Avg idle current DCX
Maximum starting current
(peak DC) DC		3σ	[3]	0.78	2.08	0.80	2.08	0.86	2.08
(peak AC) AC		3σ	[3]	1.18	3.70	1.17	3.70	1.27	3.65
Delayed motor start (max) DC		3σ	[1] [4]	0.44	0.03	0.47	0.03	0.52	0.03
Peak operating current:
			[1] [6]	0.62	0.89	0.76	0.88	0.52	0.87
Typical DCX
Maximum DC		3σ	[1]	0.75	0.93	0.77	0.94	0.80	0.93
Maximum (peak) DC		3σ		1.54	2.68	1.54	2.70	1.60	2.62

Table 4:	DC power requirements for ST373455FC model
				1 Gbit		2 Gbit		4 Gbit
			Notes	(Amps)	(Amps)	(Amps)	(Amps)	(Amps)	(Amps)
Voltage				+5V	+12V [2]	+5V	+12V [2]	+5V	+12V [2]
Regulation			[5]	±5%	±5% [2]	±5%	±5% [2]	±5%	±5% [2]
			[1] [7]	0.76	0.41	0.83	0.42	0.84	0.41
Avg idle current DCX
Maximum starting current
(peak DC) DC		3σ	[3]	0.77	2.02	0.80	2.02	0.84	2.02
(peak AC) AC		3σ	[3]	1.10	3.51	1.17	3.57	1.29	3.48
Delayed motor start (max) DC		3σ	[1] [4]	0.45	0.03	0.49	0.03	0.53	0.03
Peak operating current:
			[1] [6]	0.69	0.73	0.74	0.74	0.78	0.76
Typical DCX
Maximum DC		3σ	[1]	0.71	0.79	0.77	0.79	0.81	0.80
Maximum (peak) DC		3σ		1.42	2.46	1.54	2.48	1.56	2.50

[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 15000 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 when the Motor Start option is enabled and the drive has not yet received a Start Motor command.

[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 309 s I/Os per second for ST3300655FC and

24 Cheetah 15K.5 FC Product Manual, Rev. F