User Manual

Seagate SkyHawk Serial ATA Product Manual, Rev. B 12
www.seagate.com Drive specifications
1.2.5.2 Conducted noise
Noise is specified as a periodic and random distribution of frequencies covering a band from DC to 10 MHz. Maximum
allowed noise values given below are peak-to-peak measurements and apply at the drive power connector.
1.2.5.3 Voltage tolerance
Voltage tolerance (including noise):
5V ± 5% 12V ± 10%
1.2.5.4 Extended Power Conditions - PowerChoice
TM
Utilizing the load/unload architecture a programmable power management interface is provided to tailor systems for
reduced power consumption and performance requirements.
The table below lists the supported power conditions available in PowerChoice. Power conditions are ordered from
highest power consumption (and shortest recovery time) to lowest power consumption (and longest recovery time)
as follows: Idle_a power >= Idle_b power >= Idle_c power >= Standby_z power. The further users go down in the
table, the more power savings is actualized. For example, Idle_b results in greater power savings than the Idle_a
power condition. Standby results in the greatest power savings.
Each power condition has a set of current, saved and default settings. Default settings are not modifiable. Default and
saved settings persist across power-on resets. The current settings do not persist across power-on resets. At the time
of manufacture, the default, saved and current settings are in the Power Conditions log match.
PowerChoice is invoked using one of two methods
 Automatic power transitions which are triggered by expiration of individual power condition timers. These timer
values may be customized and enabled using the Extended Power Conditions (EPC) feature set using the
standardized Set Features command interface.
 Immediate host commanded power transitions may be initiated using an EPC Set Features "Go to Power
Condition" subcommand to enter any supported power condition. Legacy power commands Standby Immediate
and Idle Immediate also provide a method to directly transition the drive into supported power conditions.
PowerChoice exits power saving states under the following conditions
 Any command which requires the drive to enter the PM0: Active state (media access)
 Power on reset
+5v = 250 mV pp from 100 Hz to 20 MHz.
+12v = 800 mV pp from 100 Hz to 8 KHz.
450 mV pp from 8 KHz to 20 KHz.
250 mV pp from 20 KHz to 5 MHz.
Power Condition Name Power Condition ID Description
Idle_a 81
H
Reduced electronics
Idle_b 82
H
Heads unloaded. Disks spinning at full RPM
Idle_c 83
H
Heads unloaded. Disks spinning at reduced RPM
Standby_z 00
H
Heads unloaded. Motor stopped (disks not spinning)