Seagate ST34321A Product Manual - Page 18

10 Medalist 8641, 6531, 4321, 3221 and 2110, Rev. B 1.7.1.1 Typical current profile Figure 1 shows a typical current profile Current (Amps) 1.8 1.6 1.4 1.2 1.0 0.8 0.6 0.4 0.2 0.0 0 1 2 3 4 5 6 7 8 9 Time (seconds) Figure 1. Typical startup and operation current profile 1.7.2 Conducted 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. 1.7.3 Voltage tolerance Voltage tolerance (including noise): 5V ± 5% and 12V ± 8%