Degradation mechanisms in operational amplifier precision rectifiers

Two principal degradation mechanisms that are generally present in op-amp precision rectifiers have been studied in detail. The process of rectification increases the spectral content, and subsequent band-limited signal processing causes a "loss in depth" at the zero-crossings. The second source of degradation is caused by diode feedback nonlinearity effects that cause the op-amp to become open loop, and this results in a missing segment in the final output. Total harmonic distortion is an inadequate figure of merit to quantify these two effects, and so an alternative is presented. >