A 110-dB Dynamic Range, 76-dB Peak SNR Companding Continuous-Time ?S Modulator for Audio Applications

摘要

This paper presents a companding continuous-time $DeltaSigma$ ADC for audio applications. The 3rd-order modulator uses a 3-bit companding quantizer and has an over sampling rate of 64. The companding quantizer is implemented by a log amplifier followed by a flash ADC. The modulator, in simulation, achieves a peak signal-to-noise ratio of 76 dB, a dynamic range of 110 dB in a 24 kHz bandwidth and dissipates 860 uW of power.