Real-time measurement for digital audio system using FPGA

In digital audio systems, ΔΣ modulators are generally used as analog-to-digital converters (ADCs) and digital-to-analog converters (DACs). The ΔΣ modulator has a noise-shaping property that moves quantization noise within the signal band to the higher frequency band. Therefore, a high signal-to-noise ratio (SNR) is achieved. In a system using ΔΣ modulators, digital processing is indispensable. Generally, such system was usually evaluated only by computer simulation. In this paper, we propose a novel system to evaluate real signals by using a field-programmable gate array (FPGA) in real time. Our system enables evaluations for ADCs and DACs as well as other consumer devices, such as audio visual systems.