Perhaps I'm overlooking this and thinking about this too complexly...but this is my question.

When analyzing system designs for example a PCB layout with hundreds of components...passive and active devices....how do I calculate the total output power?

I thought perhaps the best method would be to analyze datasheets for active devices...use the (typically) max power output, or output resistance...or voltages/currents and with just KCL/KVL sum up all values...

Is there perhaps a reference on this? I know my power calculations...but I'm fairly new to large scale designs and would like to refine this skill.

Thank you in advance!

 

Have you thought about power supply voltage x power supply current?

 

To collecting all the datasheets of parts that you have used.
According to the datasheets to calculating the current of each part.
Adding all the current of parts, and plus some more current about 20%~50% for backup request, 300%~500% for the motor if the system needed.

 

So you are saying look at the max output power parameters or typical of the power supply?

As an alternative, would it be practical to calculate the Thevenin equivalent circuit and calculate load from these parameters?

Thanks

 

It would help if you were more clear about what you are trying to do.

Gauge the power requirements of an existing board or the requirements of a design.

In the old days up to about TTl and LSI chips there were rules one could follow, but these days there are so many different types these rules have largely been forgotten.

It is surely simpler to build or simulate the circuit and measure?

 

By "output power" to you mean the total power from the power supply consumed by all the components in the circuit? The easy way is to simulate the circuit and measure the power consumed. The old way is to calculate the power of each and every device and add them all together, which is a lot of grunt work.

 

I basically have a system schematic of an old PCB with various components with no available models...so I'm basically just looking to find the total output power for the circuit under no load and then under full load.

 

The more information you supply the better will be the quality of the help.

So post your schematic and any other useful info.