Seagate SkyHawk Product Manual, Rev. A
12
Drive Specifications
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.
2.7.3
Supply Voltage
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:
•
Active mode
The drive is in Active mode during the read/write and seek operations.
n
Idle mode
The electronics remains powered, and the drive accepts all commands and returns to Active mode when disk access is necessary.
•
Standby mode
The drive enters Standby mode immediately 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 electronics are in low power mode, the heads are parked and the spindle is at rest. The
drive accepts all commands and returns to Active mode when disk access is necessary.
n
Sleep mode
The drive enters Sleep mode after receiving a Sleep command from the host. In Sleep mode, the electronics are in low power mode, 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.
n
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.
Note
Equivalent resistance is calculated by dividing the nominal voltage by the typical RMS read/write current.
Allowable voltage
5V ± 5%
Allowable noise/ripple
100 p-p max, 0-20 MHz
Allowable supply rise time
<100 ms
Table 5
Power modes
Power modes
Heads
Spindle
Electronics
Active (operating)
Tracking
Rotating
Full power
Idle, performance
Tracking
Rotating
Partial Power
Idle, active
Floating
Rotating
Partial Power
Idle, low power
Parked
Rotating
Partial Power
Standby
Parked
Stopped
Low Power
Sleep
Parked
Stopped
Low Power
