power measurenment circuit

[RF engin]

I am looking an electronic circuit that can approximate the power consumed by an component.

The circuit is not used to measure the input or output power level of the component. It is used to measure the component’s DC power consumption by combining measurements of the current through and the voltage across it.

 

[VVV]

Is it supposed to be all-analog or micro-based?
You can use a current monitor to measure the current (even a diff amplifier sensing the voltage across a series resistor will work). Here are some examples **broken link removed** Linear Technology also make some good ones, as do Texas Instruments.

The voltage is measured simply right after the current monitor. To multiply the values you can use a micro or an anlog multiplier, but scaling the output will be more difficult.