High solution A=D converter with analog loop filter - has inner A=D converter operated with increased scanning frequency

摘要

The fed back, interpolative A/D converter has an analog loop filter (Hcs), a coupled inner A/D converter, and a following D/A converter. The latter output signal is fed back to the loop filter input. There is an overscanning and a decimation filter (Hlz) behind the A/D converter, and reduction to a specified scanning rate. The inner A/D converter is operated with an increased scanning frequency, and the converted signal value is transmitted to the D/A converter with the next cycle of the additional overscanning rate. Pref. the additional signal values are stored in a buffer register, whose read-out cancels the additional overscanning. ADVANTAGE - 18 bits exceeding word length.