Seagate ST3250823SCE Manuel D’Utilisation

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DB35 Serial ATA Product Manual, Rev. E
9
2.8.2
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 voltage by the typical RMS read/write 
current.
2.8.3
Voltage tolerance
Voltage tolerance (including noise):
5V ± 5% 
 
12V ± 10%
2.8.4
Power-management modes
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 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 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 disc 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 
Power modes
Heads
Spindle
Buffer
Active
Tracking
Rotating
Enabled
Idle
Tracking
Rotating
Enabled
Standby
Parked 
Stopped
Enabled
Sleep
Parked
Stopped
Disabled