Product Manual - Hawk 1 Family SCSI-2 (Volume 1), Rev. D
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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
Differential
Voltage
+5 V
+12 V
+5 V
+12 V
Regulation [5]
+5%
+5%[2]
+5%
+5%[2]
Maximum Operating Current [1]
0.88 A
1.0 A
1.08 A
1.0 A
Average Idle Current [1] [3]
0.48 A
0.55 A
0.63 A
0.55 A
Maximum Starting Current (Peak)
0.88 A
2.0 A
0.98 A
2.0 A
Delayed Motor Start (Max) [4]
0.68 A
0.7 A
0.68 A
0.7 A
Peak Operating Current [6]
Typ. [1]
0.72 A
0.60 A
0.7 A
0.60 A
Max. [1]
0.88 A
1.0 A
1.08 A
1.0 A
Max. (Peak)
-
2.0 A
-
2.0 A
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[1] Measured with average reading DC ammeter. Instant12 V current peaks will exceed these
values.
[2] A -10% tolerance 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] Instantaneous peaks less than 5 msec. in duration are allowed.
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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 2.0
amperes, 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.
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