12
2.9.2
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.
2.9.3
Voltage tolerance
Voltage tolerance (including noise):
5V
5%
12V
10%
2.9.4
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:
Power modes
Active
Idle
Standby
Sleep
• 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
Barracuda ATA V Product Manual, Rev. E
Heads
Tracking
Tracking
Parked
Parked
Spindle
Rotating
Rotating
Stopped
Stopped
Buffer
Enabled
Enabled
Enabled
Disabled