User Manual

Constellation.2 SAS Product Manual, Rev. K 31
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 defined frequency range. Maximum
allowed noise values given below are peak-to-peak measurements and apply at the drive power connector.
6.3.2 Power sequencing
The drive does not require power sequencing. The drive protects against inadvertent writing during power-up and
down.
+5v = 250mVpp from 100Hz to 20MHz.
+12v = 450mVpp from 100Hz to 100KHz.
250mVpp from 100KHz to 20MHz.
150mVpp from 20MHz to 100MHz.