Computer Drive User Manual

Cheetah NS 10K.2 FC Product Manual, Rev. B 25
Measured with average reading DC ammeter. Instantaneous +12V current peaks will exceed these values.
Power supply at nominal voltage. N (number of drives tested) = 6, 35 Degrees C ambient.
[4] For +12 V, a –10% tolerance is allowed during initial spindle start but must return to ±5% before reaching
10,000 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.
[5] See +12V current profiles in Figures 1 and 2.
[6] This condition occurs when the Motor Start option is enabled and the drive has not yet received a Start
Motor command.
[7] See paragraph 6.2.1, "Conducted noise immunity." Specified voltage tolerance includes ripple, noise, and
transient response.
[8] Operating condition is defined as random 8 block reads at 320 s I/Os per second for ST3600002FC , 321
I/Os per second for ST3450802FC models, and 323 I/Os per second for ST3300602FC models. Current
and power specified at nominal voltages. Decreasing +5 volt supply by 5% increases 5 Volt current by
3.5%. Decreasing +12 volt supply by 5% increases 12 volt current by 2.5% (1.5% for ST3450802FC and
ST3300602FC models).
[9] During idle, the drive heads are relocated every 60 seconds to a random location within the band from
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.
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.
4. Parameters, other than spindle start, are measured after a 25-minute warm up.
5. No terminator power.
Table 4: DC power requirements for ST3300602FC model
1 Gbit 2 Gbit 4 Gbit
Notes (Amps) (Amps) (Amps) (Amps) (Amps) (Amps)
Voltage +5V +12V [4] +5V +12V [4] +5V +12V [4]
Regulation [5] ±5% ±5% [2] ±5% ±5% [2] ±5% ±5% [2]
Avg idle current DCX
[] [7] 0.36 0.31 0.38 0.30 0.40 0.30
Maximum starting current
(peak DC) DC 3σ [5] 0.44 1.94 0.46 1.95 0.63 1.95
(peak AC) AC 3σ [5] 0.84 3.98 0.74 3.64 1.02 3.66
Delayed motor start (max) DC 3σ [] [6] 0.44 0.04 0.46 0.04 0.48 0.04
Peak operating current:
Typical DCX [] [6] 0.38 0.60 0.40 0.60 0.42 0.60
Maximum DC 3σ [] 0.39 0.61 0.41 0.61 0.44 0.61
Maximum (peak) DC 3σ 1.00 2.38 1.02 2.44 1.04 2.40