Seagate ST3450857FC ユーザーズマニュアル
Cheetah 15K.7 FC Product Manual, Rev. C
23
[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.
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.
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.
Motor command.
[5]
See paragraph 7.2.1, "Conducted noise immunity." Specified voltage tolerance includes ripple, noise, and
transient response.
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.
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.
three-quarters to maximum track.
General DC power requirement notes.
1.
Minimum current loading for each supply voltage is not less than 1.2% of the maximum operating current
shown.
shown.
2.
The +5V and +12V supplies should employ separate ground returns.
3.
Where power is provided to multiple drives from a common supply, careful consideration for individual
drive power requirements should be noted. Where multiple units are powered on simultaneously, the peak
starting current must be available to each device.
drive power requirements should be noted. Where multiple units are powered on simultaneously, the peak
starting current must be available to each device.
4.
Parameters, other than spindle start, are measured after a 10-minute warm up.
5.
No terminator power.
Table 4:
ST3300657FC DC power requirements
2 Gbit
4 Gbit
Notes (Amps)
(Amps)
(Amps)
(Amps)
Voltage
+5V
+5V
+12V [2]
Regulation
[5]
±5%
±5% [2]
±5%
±5% [2]
Avg idle current DCX
0.39
0.59
0.39
0.59
Maximum starting current
(peak DC) DC
3
σ [3]
0.62
1.91
0.62
1.91
(peak AC) AC
3
σ [3]
0.96
3.75
0.98
3.57
Delayed motor start (max) DC
3
σ [1] [4] 0.56
0.04
0.56
0.04
Peak operating current:
Typical DCX
0.48
0.92
0.48
0.91
Maximum DC
3
σ [1]
0.53
1.00
0.53
0.95
Maximum (peak) DC
3
σ
1.32
2.80
1.32
2.72