A high precisions stereo Analog-to-Digital converter

A single die, stereo delta sigma ADC is designed for high precision measurement applications. A single loop, fifth-order, thirty-three level delta-sigma analog modulator with positive and negative feedforward path is implemented. An interpolated multilevel quantizer with unevenly weighted quantization levels replaces a conventional 5-bit flash type quantizer in this design. Circuit board layout is also optimized for achieving the performance target. Integrated with an on-chip bandgap reference circuit and decimation filter, the ADC achieves 128dB dynamic range, -114dB THD over 1kHz bandwidth.