20 Cheetah NS 10K.2 SAS Product Manual, Rev. F
7.0 Physical/electrical specificationsThis section provides information relating to the physical and electrical characteristics of the drive.
7.1 AC power requirements
None.
7.2 DC power requirements
The voltage and current requirements for a single drive are shown below. Values indicated apply at the drive
connector.
[1] Measured with average reading DC ammeter or equivalent sampling scope. Instantaneous +12V current
peaks will exceed these values. 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
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.
[3] See +12V current profile in Figure 1.
[4] This condition occurs after OOB and Speed Negotiation completes but before the drive has received the
Notify Spinup primitive.
[5] See paragraph 7.2.1, "Conducted noise immunity." Specified voltage tolerance includes ripple, noise, and
Table 12: ST3600002SS DC power requirements
Notes
1.5 Gb mode 3 Gb mode 6 Gb mode
(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]
Avg idle current DCX [1] [6] 0.35 0.37 0.38 0.36 0.32 0.35
Maximum starting current
(peak DC) DC 3σ[3] 0.48 1.81 0.60 1.81 0.48 1.80
(peak AC) AC 3σ[3] 0.82 3.60 1.02 3.60 0.84 3.71
Delayed motor start (max) DC 3σ[1] [4] 0.43 0.04 0.46 0.04 0.45 0.04
Peak operating current:
Typical DCX [1] 0.38 0.66 0.39 0.65 0.42 0.66
Maximum DC 3σ[1] 0.38 0.68 0.40 0.66 0.43 0.67
Maximum (peak) DC 3σ1.00 2.50 1.02 2.58 1.06 2.46