Efficient dithering of sigma-delta modulators with adaptive bit flipping

A new technique is presented for dithering single bit sigma-delta modulator (SDM) A/D and D/A converters in the digital domain. The system operates by detecting and randomising the limit cycle oscillations responsible for baseband tones. The system is efficient to implement in hardware and does not surfer from the analogue dither that is required in conventional SDM A/D converters. >