Dc Power; Input Noise; Power Management - Seagate ST3285N Product Manual

ST3655 Family SCSI Drives Product Manual, Rev. A

1.11 DC power

Except during the write procedure, you can apply power to the drive or
remove power from the drive in any sequence without losing data or
damaging the drive. If you remove the power from the drive during the
write procedure, you may lose the data currently being written.

1.11.1 Input noise

Voltage tolerance
(including noise)
Input noise frequency
(max)
Input noise
(max, peak-to-peak)

1.11.2 Power management

The drive supports power-management modes that reduce its overall
power consumption. The drive automatically changes from one mode to
another based in response to interface activity. You do not need to
change any parameters or send any special commands to make the drive
change modes. The power-management modes are described below.
• Spinup. The spindle is coming up to operating speed. The power
consumed in this mode is equivalent to the average power during the
first 10 seconds after the drive begins to spin up. Refer to the startup
current chart in Figure 1 on page 9 for a typical representation of power
consumption during spinup.
• Seeking. The servo electronics are active and the read/write heads
are moving to a specific location on the disc. The read/write electronics
are powered-down. The power consumed in this mode is equivalent
to the average power measured while executing random seeks with
a 2-revolution (26.6 msec) dwell between seeks. The drive enters this
mode from the Idle mode.
• Read/write. The drive is reading or writing. All electronics are active
and the read/write heads are on track. The drive enters this mode from
the Idle mode.
+5V +12V
± 5% ± 5%
25 MHz 25 MHz
240 mV
100 mV
7