The ADC + FPGA structure In a broad range of practical applications, input signals are digitized with an analog-to-digit converter (ADC), and the digital data are immediately sent to an FPGA for processing. Sophisticated signal processing functions such as ‹ltering, signal feature extraction, noise elimination, etc., can be conveniently performed digitally in an FPGA, or in microprocessors when the digital data are transported to later stages. Compared with analog approaches, digital signal processing is easier to implement, and more ¨exible for algorithm changing and parameter adjustment.