Seagate ST250VT000 ユーザーズマニュアル
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EAGATE
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IDEO
2.5 HDD P
RODUCT
M
ANUAL
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EV
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8
D
RIVE
S
PECIFICATIONS
2.7.2
Conducted noise
Input noise ripple is measured at the host system power supply across an equivalent 15-ohm resistive load on the +5 volt line.
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 20
MHz.
N
OTE
Equivalent resistance is calculated by dividing the nominal
voltage by the typical RMS read/write current.
voltage by the typical RMS read/write current.
2.7.3
Voltage tolerance
Voltage tolerance (including noise):
+5V ± 5%
2.7.4
Power management modes
The drive provides programmable power management to provide greater energy efficiency. In most systems, power management is
controlled through the system setup program. The drive features the following power-management modes:
controlled 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.
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.
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
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.
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.
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 activity is required, the drive makes a transition to
standby mode. In both Idle and standby mode, the drive accepts all commands and returns to active mode when disk access is
necessary.
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 activity is required, the drive makes a transition to
standby mode. In both Idle and standby mode, the drive accepts all commands and returns to active mode when disk access is
necessary.
Power modes
Heads
Spindle
Buffer
Active (operating)
Tracking
Rotating
Full power
Idle, performance
Tracking
Rotating
Self refresh—low power
Idle, active
Floating
Rotating
Self refresh—low power
Idle, low power
Parked
Rotating
Self refresh—low power
Standby
Parked
Stopped
Self refresh—low power
Sleep
Parked
Stopped
Self refresh—low power