analog signal processing

I would like a low power analog method to set a comparator threshold, that can be 'trained' with existing input signals. That is, given a pseudo-random signal with a particular RMS and peak-peak profile, can I train a circuit to reliably (statistically) determine that the signal profile has changed to a higher RMS/Peak-peak profile?

This would be simple in digital domain, but the circuit must be low power. The comparator would generate an interrupt to turn on the MCU and hence the rest of the system.

I've attached a sample signal - the first segment has RMS 0.0002 and the second segment 0.003 RMS. Can you recommend an analog signal process approach to reliably train a circuit to recognize that the signal has transitioned from one state to the next? Note: this has to work for any two states that can be statistically recognized as separate states, hence the 'training' aspect of this. We want the comparator threshold generation to be automated...

Many thanks for any guidance...

  • Hello,

    Analog Devices has quite a few rms RF power detectors to choose from. Some have comparator function built-in. Maybe the system MCU could take periodic measurements, send that out to a DAC which sets the comparator threshold, then go to sleep and wait for the comparator to trip. See for example the ADL5502, ADL5511, and ADL5904.   -Bruce H.