Digital excess loop delay compensation technique with embedded truncator for continuous-time delta–sigma modulators

A novel implementation is proposed to relax the specifications of the internal feedback path for a continuous-time delta–sigma modulator. A truncator is embedded into the digital excess loop delay (ELD) compensation path. Thermometer-coded truncation is achieved by re-ordering the reference voltages of the internal quantiser. This requires only a small amount of extra digital circuitry compared to the conventional digital ELD compensation. The digital encoder controlling the digital-to-analogue converter is simple, and it only introduces a small ELD.