Seagate ST340015A ユーザーズマニュアル

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 voltage by

the typical RMS read/write current.

Voltage tolerance (including noise): 

The drive provides programmable power management to provide greater
energy efficiency. In most systems, you can control power management
through the system setup program. The drive features the following power-
management modes:

The drive is in Active mode during the read/write and seek operations.

The buffer remains enabled, and the drive accepts all commands and returns
to Active mode any time disc access is necessary.

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

5V ± 5% 

12V ± 10%

Active

Tracking

Rotating

Enabled

Idle

Tracking

Rotating

Enabled

Standby

Parked Stopped

Enabled

Sleep

Parked

Stopped

Disabled