Ripple Voltage; Power Consumption Efficiency Index - IBM Ultrastar 36LZX Specifications

(All values in Amps.)
Idle Average
Idle ripple (peak-to-peak)
Seek average
Seek peak
Start up (max)
Random R/W peak
Random R/W average
Figure 33. Power supply current of DDYS-T09170

7.5.3 Ripple voltage

+5V DC
+12V DC
Figure 34. 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 load-
ing). If several files have their power daisy chained together then the power supply ripple plus other drive
dynamic loading must remain within the regulation tolerance of ± 0.5%. 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 ± 300 milivolts peak to peak level difference to the drive power connector ground.

7.5.4 Power consumption efficiency index

Model
Power consumption efficiency
index (Idle mode)
Figure 35. Power consumption efficiency index
+5 Volts +5 Volts
Pop Mean Std. Dev
0.62 0.02
0.20 0.02
0.65 0.02
0.93 0.05
0.94 0.03
1.30 0.10
0.75 0.02
Maximum
250 [mV pp]
250 [mV pp]
DDYS-T36950
0.35 [W/GB]
Ultrastar 36LZX hard disk drive specifications
+12 Volts
Pop Mean
0.45
0.70
1.25
2.30
2.50
2.30
0.82
Notes
0-10 [MHz]
0-10 [MHz]
DDYS-T18350
0.53 [W/GB]
41
+12 Volts Total (W)
Std. Dev
0.03 8.5
0.10 n/a
0.03 18.3
0.10 n/a
0.13 n/a
0.10 n/a
0.03 13.6
DDYS-T09170
0.93 [W/GB]