Improved Sayiner level crossing ADC

Abstract

We present simulations showing the primary distortion in a Sayiner level crossing converter is odd harmonic distortion and examine two methods for improving the performance. A cosine-dither technique is presented. The potential benefits of a hybrid delta sigma level crossing converter are discussed. Nyquist analog-to-digital converters achieve high dynamic range with a large number of quantization levels. Delta sigma oversampling analog-to-digital converters achieve high dynamic range by averaging a large number of coarsely quantized samples together. A zero crossing converter determines the time when the input signal equals a reference signal. A zero crossing converter requires accurate timing to achieve high dynamic range. By combining a small number of quantization levels with zero crossing times, Sayiner's level crossing converter achieves high dynamic range with a fraction of the complexity of a Nyquist converter and requires less accurate timing than a zero crossing converter.