Sigma-Delta difference-of-squares RMS to DC converter with multiple feedback paths

摘要

Architectures of SigmaDelta difference-of-squares RMS-to-digital converters employing multiple feedback paths. Additional feedback paths enable a stable SigmaDelta closed-loop behavior in different topologies where the RMS level of the quantization error processed by the squaring non-linearity is minimized. Such feedback paths include lowpass filtered and constant gain feedback paths, lowpass and highpass filtered paths or multiple lowpass filtered paths. These can be combined with multiple integrators in the forward path, with frequency compensation provided by additional feedforward or feedback paths. Electronic configurability can further extend the total input referred dynamic range (DR) of such architectures.