18 | Barracuda 9 Installation Guide, Rev. B |
2A –10% tolerance is permissible during initial start of the spin- dle 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 9 Product Man- ual (publication number 83329030).
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 9 Product Manual. The specified voltage tolerance is inclusive of ripple, noise, and transient response.
6At power-up, the motor current regulator limits the +12V cur- rent to an average value of less than 1.4A, although instanta- neous 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 +5V and +12V supplies.
9Where power is provided to multiple drives from a common supply, carefully consider individual-drive power requirements. 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. A command is issued every 0.075 seconds (every 0.063 seconds on wide and SCA drives).
