Seagate HAWK 2 ST12400W/WD/WC Manual descargar pdf (Pagina 29)

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.

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Seagate HAWK 2 ST12400W/WD/WC Manual Pagina 29