Seagate ST320014A Computer Drive User Manual


 
8 ST320014A Product Manual, Rev. D
1.7.2 Conducted noise
Input noise ripple is measured at the host system power supply across
an equivalent 80-ohm resistive load on the +12 volt line or an equivalent
15-ohm resistive load on the +5 volt line.
Using 12-volt power, the drive is expected to operate with a maximum
of 120 mV peak-to-peak square-wave injected noise at up to 10 MHz.
Using 5-volt power, the drive is expected to operate with a maximum
of 100 mV peak-to-peak square-wave injected noise at up to 10 MHz.
Note. Equivalent resistance is calculated by dividing the nominal volt-
age by the typical RMS read/write current.
1.7.3 Voltage tolerance
Voltage tolerance (including noise): 5V ± 5% and 12V ± 10%
1.7.4 Power-management modes
The drive provides programmable power management to provide great-
er energy efficiency. In most systems, you can control power manage-
ment through the system setup program. The drive features the following
power-management modes:
Active mode
The drive is in Active mode during the read/write and seek operations.
Idle mode
The buffer remains enabled, and the drive accepts all commands and
returns to Active mode any time disc access is necessary.
Standby mode
The drive enters Standby mode when the host sends a Standby
Immediate command. If the host has set the standby timer, the drive
can also enter Standby mode automatically after the drive has been
inactive for a specifiable length of time. The standby timer delay is
Power Modes Heads Spindle Buffer
Active Tracking Rotating Enabled
Idle Tracking Rotating Enabled
Standby Parked Stopped Enabled
Sleep Parked Stopped Disabled