6.5.3 Power supply generated ripple at drive power connector
+5V DC
+12V DC
Figure 57. Power supply generated ripple at drive power connector
During drive start up and seeking 12-volt ripple is generated by the drive (referred to as dynamic loading).
If the power of several drives is daisy chained together, the power supply ripple plus the dynamic loading
of the other drives must remain within the above regulation tolerance. A common supply with separate
power leads to each drive is a more desirable method of power distribution.
To prevent external electrical noise from interfering with the performance of the drive, the drive must be
held by four screws in a user system frame which has no electrical level difference at the four screws
position and has less than ±300 millivolts peak to peak level difference to the ground of the drive power
connector.
Maximum (mV pp)
100
150
Deskstar 120GXP hard disk drive specifications
49
MHz
0-10
0-10