Seagate BARRACUDA 2LP, Руководство по эксплуатации продукта

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34 Barracuda 2LP Product Manual, Rev. D
[5] See Section 7.2.1 “Conducted noise immunity.” Specified voltage toler-
ance includes ripple, noise, and transient response.
[6] At 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.
[7] Minimum current loading for each supply voltage is not less than 4% of
the maximum operating current shown.
[8] The +5V and +12V supplies use separate ground returns.
[9] 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.
[10] Operating condition is defined as a third-stroke seek at OD and read
one track. A command is issued every 0.075 sec. (0.063 seconds on W/
WD/WC/DC drives)
[11] No terminator power. See Section 11.7.3.4.
[12] All power-saving features enabled--ASA II code only.
[13] Seeking is defined as a third-stroke seek at OD. A command is issued
every 20 msec.
[14] Read track is defined as repeat reads of track 15 with a duty cycle of
78% (N), 32% (W), 48% (WC), 60% (ND), 44% (WD), 44% (DC).
7.2.1 Conducted noise immunity
Noise is specified as a periodic and random distribution of frequencies
covering a band from DC to 10 MHz. Maximum allowed noise values given
below are peak-to-peak measurements and apply at the drive’s power
connector.
0 to 100 kHZ 100 kHz to 10 MHz
+++++
5V 150 mV 100 mV
+++++
12V 150 mV 100 mV
7.2.2 Power sequencing
The drive does not require power sequencing. The drive protects against
inadvertent writing during power-up and down. Daisy-chain operation re-
quires that power be maintained on the terminated device to ensure proper
termination of the peripheral I/O cables.
To automatically delay motor start based on the target ID (SCSI ID), select
the Delay Motor Start option and deselect the Enable Motor Start option. See
Section 10.1 for pin selection information.
To delay the motor until the drive receives a Start Unit command, select the
Enable Motor Start option.