Seagate ST32550N/ND, ST31250W/WD/WC/DC, ST32550W/WD/WC/DC Barracuda 2LP Installation Guide, Rev. E

Barracuda 2LP Installation Guide, Rev. E 17

1Measured with an average reading DC ammeter. Instanta- neous +12V current peaks will exceed these values.

2A −10% tolerance is permissible during initial start of the spindle but must return to ±5% before reaching 7,200 RPM. 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.

3See the +12V current profile in the Barracuda 2LP Product Manual (publication number 83328930).

4This condition occurs when the Motor Start option is enabled and the drive has not yet received a Start Motor command.

5See “Conducted noise immunity” in the Barracuda 2LP Product Manual.The specified voltage tolerance is inclusive of ripple, noise, and transient response.

6At power-up, the motor current regulator limits the +12V current to an average value of less than 1.4A, although instantaneous peaks may exceed this value. These peaks should measure 5 msec duration or less.

7Minimum current loading for each supply voltage is not less than 4% of the maximum operating current shown.

8Use separate ground returns for +5 and +12V supplies.

9Where power is provided to multiple drives from a common supply, carefully consider individual-drive power require- ments. Where multiple units are powered on simultaneously, be sure the peak starting current is available to each device.

10Operating condition is a third-stroke seek at OD and read one Track. The command is issued every 0.075 seconds (every 0.063 seconds on wide and SCA drives).