A power efficient delta-sigma ADC with series-bilinear switch capacitor voltage-controlled oscillator

[...]types of ADCs were used as codec and hearing aids which require large dynamic range for signal paths [1-4]. Scaling of voltage is applicable to digital circuit design in reducing the heat dissipation at the trade-off of speed factor.Several techniques have been reported to address this problem such as body-driven circuits, SAR operation, sub-threshold operation [6-9] and zero crossing circuits [10, 11] and the performance of these circuits were very less.The delta-sigma ADC is a very efficient structure with oversampling and noise shaping properties.The process scaling factor and bandwidth has been improved in continuous ASADC. [...]the performance of ADC can be improved by transferring the signal processing task to digital domain and by applying proper scaling methodology. Two stage differential operational amplifier Op-amp is the most important block of ADC and in CMOS technology the design of operational amplifiers is a challenge as the transistor channel length and voltage reduces.