Seagate ST12550N/ND/W/WD, ST11950N/ND/W/WD manual ST11950 and ST12550 Installation Guide, Rev. D

ST11950 and ST12550 Installation Guide, Rev. D				17
DC power requirements
for ST11950W/WD and ST12550W/WD drives
	Single-ended		Differential
	+5V	+12V	+5V	+12V
Voltage regulation5	± 5%	± 5%2	± 5%	± 5%2
Maximum operating current1		Amps
	1.04	0.95	1.3	0.95
Average idle current1, 12	0.76	0.83	0.83	0.83
Maximum starting current
Peak DC3, 6	1.0	2.18	1.1	2.18
Peak AC3	−	3.1	−	3.1
Delayed motor start (max)1, 4	1.0	0.19	1.1	0.19
Peak operating current
Typ DC1, 10	1.03	0.91	1.21	0.91
Max DC1	1.04	0.95	1.3	0.95
Max (peak)	1.2	1.87	2.0	1.87
Track following (DC)
at OD1	1.0	0.84	1.1	0.84
at ID1	1.0	0.9	1.1	0.9
Read track
OD DC1, 15	1.1	0.85	1.4	0.85
AC	1.3	1.2	2.0	1.2
Seeking
Typical DC1, 13	1.0	1.2	1.1	1.2
Maximum DC1	1.1	1.2	1.2	1.2
Maximum (peak) AC	1.2	1.8	2.0	1.8

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

continued