Seagate ST4000DX001 User Manual

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 10MHz.

• 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 10MHz.

Voltage tolerance (including noise):

• 5V

±5%

• 12V 

+10% / -7.5%

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:

• 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 disk
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 established using a Standby or Idle command. In
Standby mode, the

 

drive buffer is enabled, the heads are parked and the spindle is at rest. The drive accepts

all commands and returns to Active mode any time disk access is necessary.

• Sleep mode

The drive enters Sleep mode after receiving a Sleep command from the host. In Sleep mode, the drive buffer is
disabled, the heads are parked and the spindle is at rest. The drive leaves Sleep mode after it receives a Hard
Reset or Soft Reset from the host. After receiving a reset, the drive exits Sleep mode and enters Standby mode
with all current translation parameters intact.

• Idle and Standby timers

Each time the drive performs an Active function (read, write or seek), the standby timer is reinitialized and
begins counting down from its specified delay times to zero. If the standby timer reaches zero before any drive

Equivalent resistance is calculated by dividing the nominal voltage by the typical RMS read/write current.

Active

Tracking

Rotating

Enabled

Idle

Tracking

Rotating

Enabled

Standby

Parked Stopped

Enabled

Sleep

Parked

Stopped

Disabled