An analog-to-digital converter with dynamic window for optimal rational number approximation

This paper presents an analog-to-digital converter with a dynamic window that can realize an optimal rational number approximation. The converter encodes a DC input to a binary output sequence with code length l and the window extracts information that enables us to approximate an input by the closest fraction in a set of fractions with denominator l or less. This encoding property can be guaranteed theoretically. Presenting a basic test circuit, including a time-variant resistor, the basic operation is confirmed experimentally.