Cheetah 15K.6 FC Product Manual, Rev. A
[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.
[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.
[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.
[5] See paragraph 6.2.1, "Conducted noise immunity." Specified voltage tolerance includes ripple, noise, and
transient response.
[6] Operating condition is defined as random 8 block reads at 330 I/Os per second for ST3450856FC and
Table 3: DC power requirements for ST3300656FC model
1 Gbit 2 Gbit 4 Gbit
Notes (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] [7] 0.45 0.68 0.48 0.68 0.53 0.67
Maximum starting current
(peak DC) DC 3σ [3] 0.62 1.77 0.64 1.78 0.83 1.78
(peak AC) AC 3σ [3] 0.74 4.27 0.84 4.15 1.15 4.23
Delayed motor start (max) DC 3σ [1] [4] 0.43 0.04 0.45 0.04 0.50 0.04
Peak operating current:
Typical DCX [1] [6] 0.48 1.09 0.58 1.09 0.58 1.08
Maximum DC 3σ [1] 0.50 1.11 0.61 1.11 0.59 1.11
Maximum (peak) DC 3σ 0.98 2.62 1.12 2.66 1.16 2.72
Table 4: DC power requirements for ST3146356FC model
1 Gbit 2 Gbit 4 Gbit
Notes (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] [7] 0.55 0.53 0.58 0.53 0.64 0.53
Maximum starting current
(peak DC) DC 3σ [3] 0.69 1.82 0.72 1.81 0.98 1.81
(peak AC) AC 3σ [3] 0.84 3.85 0.88 3.79 1.17 3.90
Delayed motor start (max) DC 3σ [1] [4] 0.49 0.03 0.52 0.03 0.59 0.04
Peak operating current:
Typical DCX [1] [6] 0.63 0.92 0.66 0.91 0.69 0.91
Maximum DC 3σ [1] 0.63 0.95 0.66 0.95 0.71 0.94
Maximum (peak) DC 3σ 1.10 2.40 1.16 2.46 1.20 2.48
