Seagate ST336854FC, ST3146954FC, ST373554FC manual See +12V current profile in Figure

Table 3:	DC power requirements for ST373554FC drives
				1 Gbit mode		2 Gbit mode		4 Gbit mode
			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]	0.62	0.57	0.66	0.56	0.69	0.57
Avg idle current DCX
Maximum starting current
(peak DC) DC		3σ	[3]	0.83	1.88	0.94	1.85	0.77	1.71
(peak AC) AC		3σ	[3]	0.98	4.08	1.11	4.08	1.17	2.94
Delayed motor start (max) DC		3σ	[1] [4]	0.54	0.03	0.58	0.04	0.70	0.04
Peak operating current:
			[1] [6]	0.79	1.01	0.90	0.66	0.76	0.79
Typical DCX
Maximum DC		3σ	[1]	0.82	1.03	1.18	0.67	0.77	0.80
Maximum (peak) DC		3σ		1.27	2.82	1.24	2.98	1.30	2.82

Table 4:	DC power requirements for ST336854FC drives
				1 Gbit mode		2 Gbit mode		4 Gbit mode
			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]	0.62	0.43	0.66	0.43	0.69	0.43
Avg idle current DCX
Maximum starting current
(peak DC) DC		3σ	[3]	0.83	1.59	0.93	1.58	0.98	1.59
(peak AC) AC		3σ	[3]	0.99	3.43	1.11	3.30	1.16	3.36
Delayed motor start (max) DC		3σ	[1] [4]	0.55	0.03	0.58	0.03	0.62	0.03
Peak operating current:
			[1] [6]	0.77	0.87	0.81	0.86	0.84	0.87
Typical DCX
Maximum DC		3σ	[1]	0.81	0.89	0.85	0.88	0.88	0.88
Maximum (peak) DC		3σ		1.26	2.64	1.31	2.54	1.35	2.59

[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 14,904 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 2.

[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 225 I/Os per second for ST3146954FC models

26 Cheetah 15K.4 FC Product Manual, Rev. B