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DiamondMax 21 Serial ATA Product Manual, Rev. A
Figure 2. Typical 12V startup and operation current profile
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 -pea k square-w ave
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.
Power modes Heads Spindle Buffer
Active Tracking Rotating Enabled
Idle Tracking Rotating Enabled
Standby Parked Stopped Enabled
Sleep Parked Stopped Disabled