Seagate Cheetah ST173404FC, Руководство по эксплуатации продукта, Страница: 32 / 80

22 Cheetah 73FC Product Manual, Rev. C
6.2.1 Conducted noise immunity
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 con-
nector.
6.2.2 Power sequencing
The drive does not require power sequencing. The drive protects against inadvertent writing during power-up
and down.
6.2.3 Current profiles
Figure 3 identifies the drive +12V current profile and Figure 4 identifies the drive +5V current profile. The cur-
rent during the various times is as shown:
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.
T3 Spindle is up to speed and the Head-Arm restraint is unlocked.
T4 The adaptive servo calibration sequence is performed.
Note: All times and currents are typical. See Table 1 for maximum current requirements.
Figure 3. Typical Cheetah 73FC drive +12V current profile
+5V +12V (with spindle motor not running)
0 to 100 kHz 150mV 150mV
100 kHz to 10 MHz 100mV 100mV
0 4 8 12 16 20 24 28 32
0.0
1.0
2.0
A
3.0
4.0
Seconds
Envelope of waveform
T0 T2 T3 T4 T5
+12 Volt Current during spindle start – Typical Amperes
T1
Average value of waveform