SIGMA-DELTA DIFFERENCE-OF-SQUARES LOG-RMS TO DC CONVERTER WITH FORWARD PATH MULTIPLIER AND CHOPPER STABILIZATION

摘要

A sigma-delta (S?) difference-of-squares LOG-RMS to digital converter for true RMS detection by merging a S? modulator with an analog LOG-RMS to DC converter based on a difference-of-squares. Chopper-stabilization, implemented through commutators running at two different frequencies, can be employed to reduce sensitivity to DC offsets and low-frequency errors, resulting in an extension of the useful input-referred dynamic range. High-order S? LOG- RMS converters can be implemented with a loop filter containing multiple integrators and feedforward and/or feedback paths for frequency compensation. The resulting implementations are S? difference-of-squares LOG-RMS to DC converters with a natural digital output and a logarithmically compressed dynamic range.