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...
This paper presents the design of a continuous-time ΔΣ modulator (CTDSM) to be used in an ultrasound beamformer for biomedical imaging. To achieve better resolution, the prototype modulator operates at 1.2 GHz. It incorporates a digital excess loop delay (ELD) compensation to replace the active adder in front of the...