Seagate ST3300555SS ユーザーズマニュアル

Cheetah T10 SAS Product Manual, Rev. A

25

Degrees C ambient.

[2]

For +12 V, a –10% tolerance is allowed during initial spindle start but must return to ±5% before reaching 
15,000 RPM. The ±5% must be maintained after the drive signifies that its power-up sequence has been 
completed and that the drive is able to accept selection by the host initiator. 

[3]

See +12V current profile in Figures 2, 3, and 4.

[4]

This condition occurs after OOB and Speed Negotiation completes but before the drive has received the 
Notify Spinup primitive.

[5]

See paragraph 6.2.1, "Conducted noise immunity." Specified voltage tolerance includes ripple, noise, and 
transient response.

[6]

During idle, the drive heads are relocated every 60 seconds to a random location within the band from 
three-quarters to maximum track.

1.

Minimum current loading for each supply voltage is not less than 1.7% of the maximum operating current 
shown. 

2.

The +5V and +12V supplies should employ separate ground returns. 

3.

Where power is provided to multiple drives from a common supply, careful consideration for individual 
drive power requirements should be noted. Where multiple units are powered on simultaneously, the peak 
starting current must be available to each device.

4.

Parameters, other than spindle start, are measured after a 10-minute warm up.

5.

No terminator power.

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. 

The drive does not require power sequencing. The drive protects against inadvertent writing during power-up 
and down.

The +12V and +5V current profiles for these drive are shown below in the following figures.

Note: All times and currents are typical. See Tables 2, 3, and 4 for maximum current requirements.

0 to 100 kHz

150mV

150mV

100 kHz to 10 MHz

100mV

100mV