Seagate ST340211AS, ST3120811AS manual Typical current profiles, Conducted noise, Voltage tolerance

2.8.1.1Typical current profiles

Figure 1. Typical 5V startup and operation current profile

Figure 2. Typical 12V startup and operation current profile

2.8.2Conducted noise

Input noise ripple is measured at the host system power supply across an equivalent 80-ohm resistive load on the +12 volt line or an equivalent 15-ohm resistive load on the +5 volt line.

•Using 12-volt power, the drive is expected to operate with a maximum of 120 mV peak-to-peak square-wave injected noise at up to 10 MHz.

•Using 5-volt power, the drive is expected to operate with a maximum of 100 mV peak-to-peak square-wave injected noise at up to 10 MHz.

Note. Equivalent resistance is calculated by dividing the nominal voltage by the typical RMS read/write current.

2.8.3Voltage tolerance

Voltage tolerance (including noise):

5V ± 5%

12V ± 10%

14 Barracuda 7200.9 Serial ATA Product Manual, Rev. C