Current Profile; Figure 3A. Typical Barracuda 18Xl Family Drive +12 V Current Profile - Seagate ST318436LW Product Manual

Barracuda 18XL Product Manual, Rev. A
6.2.3

Current profile

Figures 3a and 3b identify the drive +5 V and +12 V current profile. The current during the various times is as
shown:
T - Power is applied to the drive.
T1 - Controller self tests are performed.
T2 - Spindle begins to accelerate under current limiting after performing drive internal
diagnostics. See Note 1 of Table 2.
T3 - The heads move from the landing zone to the data area.
T4 - The adaptive servo calibration sequence is performed.
T5 - Calibration is complete and the drive is ready for reading and writing.
Note. All times and currents are typical. See Table 2 for maximum current requirements.
+12 Volt Current during spindle start – Typical Amperes
3.0
2.5
2.0
A
1.5
1.0
0.5
0.0
T T1
0.0 2
Figure 3a. Typical Barracuda 18XL family drive +12 V current profile
AC Envelope
Nominal (average)
DC curve
T2
T3
4 6 8
T4
10 12 14
Seconds
T5
16 18 20
23