Seagate Cheetah 18LP, Product Manual, Page: 29 / 94

Cheetah 18LP Product Manual, Rev. F 19
6.0 Physical/electrical specifications
This section provides information relating to the physical and electrical characteristics of the Cheetah 18LP
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 table shows current values in Amperes.
Table 2: DC power requirements
[1] Measured with average reading DC ammeter or equivalent sampling scope. Instantaneous current peaks
will exceed these values. Power supply at nominal voltage. N = 6, 22 Degrees C ambient.
[2] For +12 V, a –10% tolerance is permissible during initial start of spindle, and must return to ±5% before
10,000 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 3.
[4] This condition occurs when the Motor Start Option is enabled and the drive has not yet received a Start
Motor command.
[5] See Section 6.2.1 “Conducted Noise Immunity.” Specified voltage tolerance is inclusive of ripple, noise,
and transient response.
Notes
ST318203 ST39103
SE mode LVD mode SE mode LVD mode
Voltage +5 V +12 V +5 V +12 V +5 V +12 V +5 V +12 V
Regulation [5] ±5% ±5%[2] ±5% ±5% [2] ±5% ±5% [2] ±5% ±5% [2]
Average idle current DCX [1][7] 0.69 0.6 0.71 0.6 0.71 0.34 0.72 0.34
Maximum starting current
(peak DC) DC
(peak AC) AC [3]
[3] 0.79
1.0 1.53
2.4 0.81
1.03 1.53
2.4 0.81
0.94 1.4
2.2 0.82
0.95 1.4
2.2
Delayed motor start (max) DC [1][4] 0.61 0.02 0.62 0.02 0.62 0.02 0.65 0.02
Peak operating current
DCX
Maximum DC
Maximum (peak) DC [1][6]
[1] 0.76
0.79
1.05 1.03
1.13
2.66 0.82
0.84
1.27 1.03
1.13
2.66 0.79
0.80
1.06 0.81
0.84
2.2 0.84
0.85
1.27 0.81
0.84
2.2
ST318233 ST39133
SE mode LVD mode SE mode LVD mode
Voltage +5 V +12 V +5 V +12 V +5 V +12 V +5 V +12 V
Regulation [5] ±5% ±5%[2] ±5% ±5% [2] ±5% ±5% [2] ±5% ±5% [2]
Average idle current DCX [1][7] 0.8 0.65 0.88 0.65 0.8 0.45 0.88 0.45
Maximum starting current
(peak DC) DC
(peak AC) AC [3]
[3] 0.82
1.1 1.61
3.1 0.90
1.13 1.61
3.1 0.81
1.1 1.71
3.1 0.89
1.12 1.71
3.1
Delayed motor start (max) DC [1][4] 0.67 0.04 0.76 0.04 0.67 0.04 0.76 0.04
Peak operating current
DCX
Maximum DC
Maximum (peak) DC [1][6]
[1] 0.82
0.83
0.91 1.09
1.13
2.4 0.92
0.93
1.18 1.09
1.13
2.4 0.82
0.83
0.95 0.88
0.98
2.24 0.92
0.93
1.19 0.88
0.98
2.24