12V Current Profile; Figure 14. Typical Barracuda 4 Drive 12V Current Profile - Seagate ST15150N - Barracuda 4.3 GB Hard Drive Product Manual

ST15150N/ND/W/WD/WC/DC Product Manual, Rev. D
7.2.3
3.0
2.85
2.5
2.0
1.9
1.5
1.0
0.5
T0
T1
0.0
0

12V current profile

Figure 14 identifies the drive's 12V current profile. The current during the
various times is as shown.
Peak AC
Minimum AC
T2
5 10

Figure 14. Typical Barracuda 4 drive 12V current profile

T0 Power is applied to the drive.
T1 Controller self-tests are performed.
T2 Spindle begins to accelerate under current limiting after performing
internal diagnostics. See Note 1 of Table 1.
T3 The spindle is up to speed and the head-arm restraint is unlocked.
T4 Heads move from the landing zone to the data area.
T5 The adaptive calibration sequence is performed.
T6 Thermal calibration.
T7 Calibration is complete and the drive is ready for reading and writing.
Note. All times and currents are typical. See Table 1 for maximum current
requirements.
Nominal (average) curve
T5
T3
T4
15
TIME (S)
T6
T7
20 25
35
30