#### engr_joni_ee

##### Advanced Member level 3

The main input to the power distribution board is 20 V. This 20 V on the power distribution board is connected to two DC-DC converters having adjustable outputs. There are two identical DC-DC converters on the power distribution board.

Now each DC-DC converter is powering up further three linear voltage regulators. Each linear voltage regulator has an output connected to the load that require 1 A current and the voltage requirement of the load is 2 V.

If we set the output of the DC-DC converter to 2.5 V and feed 2.5 V to three linear voltage regulators then what will be the input current of each linear voltage regulator ? Given that each linear voltage regulator output is set at 2 V and the load current is 1 A. The input to each linear regulator is 2.5 V. The voltage drop across each linear voltage regulator will be 0.5 V which multiplied by the current is the power dissipation which is like 0.5 Watt per linear voltage regulator. In total there are six linear regulators on the power distribution board.

How can I calculate the input power for linear regulators ?

I am doing this

Power = 6 x Voltage X Current

Power = 6 x 2.5 X 1

Power = 15 Watts

How do I calculate the input power at the DC-DC converters which will be the power budget of the power distribution board. There are two DC-DC converters. How can I calculate an estimate for the power distribution board ?