Physical/Electrical Specifications; Ac Power Requirements; Dc Power Requirements - Seagate ST318436LW Product Manual

Barracuda 18XL Product Manual, Rev. A
6.0

Physical/electrical specifications

This section provides information relating to the physical and electrical characteristics of the Barracuda 18XL
drive.
6.1

AC power requirements

None.
6.2

DC power requirements

The voltage and current requirements for a single drive are shown in the following table. Values indicated apply
at the drive power connector. The single ended power requirements includes the internal disc drive SCSI I/O ter-
mination. The table shows current values in Amperes. See also Figure 3c for current values vs. number of I/O
operations.
Table 2: DC power requirements
18.373 GB drives
Voltage
Regulation
Average idle current DCX
Maximum starting current
(peak DC)
(peak AC)
Delayed motor start (max) DC
Peak operating current
Typical DCX
Maximum DC
Maximum (Peak)
9.186 GB drives
Voltage
Regulation
Average idle current DCX
Maximum starting current
(peak DC)
(peak AC)
Delayed motor start (max) DC
Peak operating current
Typical DCX
Maximum DC
Maximum (Peak)
Notes.
[1] Measured with average reading DC ammeter. Instantaneous +12 V current peaks will exceed these val-
ues. Power supply is at nominal voltages.
[2] For +12 V, a –10% droop is permissible during initial start of spindle, and must return to ±5% before 7,200
rpm is reached. 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 +12 V current profile in Figure 3a.
[4] This condition occurs when the Motor Start Option is enabled and the drive has not yet received a Start
Motor command.
ST318436
Notes LW/LC–LVD
+5 V +12 V +5 V
[5][2] ±5% ±5%
[1] 0.80 0.30
[3] 1.0 2.4
[3] 2.7
[1][4] 0.70 0.05
[1][6] 0.90 0.60
[1] 1.10 0.70
1.60 2.50
ST39236
Notes LW/LC–LVD
+5 V +12 V +5 V
[5][2] ±5% ±5%
[1] 0.80 0.25
[3] 1.0 1.7
[3] 2.4
[1][4] 0.70 0.05
[1][6] 0.90 0.50
[1] 1.00 0.80
1.40 2.30
ST318426
LWV/LCV–LVD LW/LC–LVD
+12 V +5 V
±5% ±5% ±5%
0.80 0.30 0.80
1.0 2.4 1.0
2.7
0.70 0.05 0.70
0.90 0.60 0.90
1.10 0.70 1.10
1.60 2.50 1.60
ST39226
LWV/LCV–LVD LW/LC–LVD
+12 V +5 V
±5% ±5% ±5%
0.80 0.25 0.80
1.0 1.7 1.0
2.4
0.70 0.05 0.70
0.90 0.50 0.90
1.00 0.80 1.00
1.40 2.30 1.40
ST318416
N/W–SE
+12 V +5 V +12 V
±5% ±5% ±5%
0.30 0.80 0.30
2.4 1.0 2.4
2.7 2.7
0.05 0.70 0.05
0.60 0.90 0.60
0.70 1.10 0.70
2.50 1.60 2.50
ST39216
N/W–SE
+12 V +5 V +12 V
±5% ±5% ±5%
0.25 0.80 0.25
1.7 1.0 1.7
2.4 2.4
0.05 0.70 0.05
0.50 0.90 0.50
0.80 1.00 0.80
2.30 1.40 2.30
21