Conducted Noise; Voltage Tolerance; Power-Management Modes - Seagate LD25 - Series 20 GB Hard Drive Product Manual

Additional details
Upon system power up, PHY communication is initiated with a COMRESET signal, which is generated by the
host-side transceiver. COMRESET is followed by a COMINIT signal generated by the disc drive transceiver.
COMRESET and COMINIT are followed by an exchange of COMWAKE signals and Align primitives. The disc
drive will spin up after the successful exchange of Align primitives cause the PHY to come ready.
For more details, refer to:
• Section 6.8 of the Serial ATA 1.0 High-Speed Serialized AT Attachment specification
• Section 6.2 of the Serial ATA II: Extensions to Serial ATA 1.0 specification
• SATA 1.0 design guides
Note. These specifications and guides are available on the Serial ATA web site (www.serialata.org).
2.9.3

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 10 MHz.
Note. Equivalent resistance is calculated by dividing the nominal voltage by the typical RMS read/write
current.
2.9.4

Voltage tolerance

Voltage tolerance (including noise):
5V ± 5%
2.9.5

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:
Table 4: Power management modes
Power modes
Active (operating)
Idle, performance
Idle, active
Idle, low power
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.
LD25 Series SATA Product Manual, Rev. C
Heads Spindle
Tracking Rotating
Tracking Rotating
Floating Rotating
Parked Rotating
Parked Stopped
Parked Stopped
Buffer
Enabled
Enabled
Disabled
Disabled
Disabled
Disabled
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