A VCO Based Digital Microphone Utilizing A FIR Sigma Delta Converter

Abstract

As negative feedback in control systems is often not applicable and/or produces undesirable effects, this paper presents an analysis and simulation of a finite impulse response (FIR) sigma delta A/D converter comprising of a voltage controlled oscillator (VCO) and D-flip-flop to digitize data. The FIR sigma delta modulator (SDM) is analyzed in terms of performance and simulation results are given. As an application example conventional condenser microphones are introduced and then improved upon utilizing the FIR sigma delta modulator. Proof-of-concept is given along with simulation results