Conducted Noise Immunity; Power Sequencing; Current Profiles; Figure 1. 2Tb Model Current Profiles - Seagate Enterprise Capacity 3.5 HDD/Constellation ES Product Manual

General DC power requirement notes.
1. Minimum current loading for each supply voltage is not less than 1.7% of the maximum operating current shown.
2. The +5V and +12V supplies should employ separate ground returns.
3. Where power is provided to multiple drives from a common supply, careful consideration for individual drive power requirements
should be noted. Where multiple units are powered on simultaneously, the peak starting current must be available to each device.
4. Parameters, other than spindle start, are measured after a 10-minute warm up.
5. No terminator power.
6.3.1

Conducted noise immunity

Noise is specified as a periodic and random distribution of frequencies covering a band from DC to 10 MHz. Maximum allowed noise
values given below are peak-to-peak measurements and apply at the drive power connector.
+5v = 250 mV pp from 100 Hz to 20 MHz.
+12v = 800 mV pp from 100 Hz to 8 KHz.
450 mV pp from 8 KHz to 20 KHz.
250 mV pp from 20 KHz to 5 MHz.
6.3.2

Power sequencing

The drive does not require power sequencing. The drive protects against inadvertent writing during power-up and down.
6.3.3

Current profiles

The +12V (top) and +5V (bottom) current profiles for the Constellation ES.1 drives are shown below.
Figure 1. 2TB model current profiles
Note: All times and currents are typical. See Table 2 for maximum current requirements.
C ES.1 SAS P
ONSTELLATION
M , R . G
RODUCT ANUAL EV
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