Product manual

Product Manual - Hawk 2 Family (Wide bus) SCSI-2 (Volume 1), Rev. B 21
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7.0 Physical/electrical specifications
7.1 AC power requirements: None
7.2 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.
Table 7.2-1. DC power requirements
Single Ended (W/WC) Differential (WD)
Voltage +5 V +12 V +5 V +12 V
Regulation [5] +5% +5%[2] +5% +5%[2]
Average Idle Current [1] [3] 0.43 A 0.57 A 0.57 A 0.66 A
Maximum Starting Current (Peak) [6] 0.8 A 2.4 A 0.9 A 2.4 A
Delayed Motor Start (Max) [4] [6] 0.6 A 0.4 A 0.6 A 0.4 A
Operating Current [7]
Typ. [1] 0.78 A 0.68 A 1.05 A 0.78 A
Max. [1] 1.0 A 1.0 A 1.2 A 1.0 A
Max. (Peak) - 2.4 A - 2.4 A
[1] Measured with average reading DC ammeter. Instantaneous +12 V currentpeaks will exceed these val-
ues.
[2] A droop of up to -10% is permissible during power up. 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 level T6 in Figure 7.2.2-1.
[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 7.2.1 “Conducted Noise Immunity”.
[6] Peaks of 0.90 A (nominal) on the +12 V will occur for no more than 100 ms total during the first 250 ms
after power is applied.
[7] Instantaneous peaks less than 5 msec. in duration are allowed.
General Notes from Table 7.2-1:
1. At powerup, the motor current regulator limits the 12 volt current to a peak value of less than 2.4 am-
peres, although instantaneous peaks may exceed this value. These peaks should measure 5 msec.
duration or less.
2. Operating condition is defined as Random Seek Reads of 64 blocks.
3. Minimum current loading for each supply voltage is not less than 30% of the maximum operating current
shown.
4. The +5 and +12 volt supplies shall employ separate ground returns.
5. 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.