i am using AT 89S52 microcontroller and we want to measure average value of a signal with frequency between 10khz-15khz. is there any ADC IC available which will directly give me an average value ? if there is any other solution please let me know.
That is one valid method of measuring the pulse quote or the RMS or whatever for a rectangular wave of known amplitude.
If the amplitude isn't known, then it is possible to measure the peak voltage together with edge-detection.
There are a lot of special cases available as long as the wave-form or amplitude is known.