IBM DCAS-32160 - Ultrastar 2.1 GB Hard Drive, Specifications

Page: 52 / 232

During drive start up and seeking, 12 volt ripple is generated by the drive (referred to as dynamic loading). If
several files have their power daisy chained together then the power supply ripple plus other drive's dynamic
loading must remain within the regulation tolerance of + 1 0 / - 8 % . 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 drive's performance, 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 + / - 3 0 0 milivolts peak to peak level difference to the drive power connector ground.
6.5.1 Start Up Current
Figure 32. Power Supply Generated Ripple at Drive Power Connector
Maximum Notes
+ 5 V D C 100 [ mV pp] 0-10 [ MHz]
+ 1 2 V D C 150 [ mV pp] 0-10 [ MHz]
Figure 33. Typical Current Wave F o r m of 12V at Start Up of DCAS-32160
38
O E M Spec. of DCAS-34330/32160