Product manual

Cheetah 4LP FC Product Manual, Rev. A 17
6.0 Physical/electrical specifications
This section provides information relating to the physical and electrical characteristics of the drive.
6.1 AC power requirements
None.
6.2 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. Instantaneous +12V current peaks will exceed these val-
ues.
[2] A –10% tolerance is allowed during initial spindle start but must return to ±5% before reaching 10,033
RPM. The ±5% must be maintained after the drive signifies that its power-up sequence has been com-
pleted and that the drive is able to accept selection by the host initiator.
[3] See +12V 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 paragraph 6.2.1, “Conducted noise immunity.” Specified voltage tolerance includes ripple, noise, and
transient response.
[6] At power-up the motor current regulator limits the 12V current to an average value of less than 2.5 - 2.7A,
although instantaneous peaks may exceed this value. These peaks should measure 5 msec duration or
less.
[7] Operating condition means a third stroke seek at OD and Read One track. A command is issued every
0.108 seconds.
[8] All power-saving features enabled.
General DC power requirement notes.
1. Minimum current loading for each supply voltage is not less than 4% 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.
Table 1: DC power requirements
ST34501FC
Voltage Regulation Notes [5]
+5V
±5%
(Amps)
+12V
±5%[2]
(Amps)
Avg idle current [1] [8] 1.000 0.874
Max start current (peak DC) [3] [6] 1.074 2.239
Delayed motor start (max) [1] [4] 0.634 0.177
Operating current: [7]
Typical [1] [6] 1.036 1.028
Maximum [1] 1.083 1.075
Max (peak) 1.239 2.196