Deskstar 7K500 and Deskstar E7K500 Hard Disk Drive Specification
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7.3.3 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.
Table 48: Power supply current of SATA model
Power supply current of SATA
model
+5 Volts [mA] +12 Volts [mA] Total
[W]
(values in milliamps. RMS) Pop Mean Std Dev Pop Mean Std Dev
Idle average 500 12 590 12
9.6
Idle ripple (peak-to-peak) 330 40 630 20
Low RPM Idle 300 7 280 10
5.1
Low RPM Idle Ripple 220 30 380 20
Unload Idle average 350 7 480 13
7.5
Unload Idle Ripple 220 35 600 20
Random R/W average
2
670 9 850 20
13.6
Random R/W peak 1600 50 2100 60
Silent R/W average 710 9 660 15
11.5
Silent R/W peak 1600 50 1350 40
Start up (max) 1190 50 2000 75
Standby average 280 9 20 3 2.0
Sleep average 220 8 20 3 1.7
Table 49: Power supply generated ripple at drive power connector
Maximum (mV pp) MHz
+5 V dc 100 0-10
+12 V dc 150 0-10
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