Capacitor array logic control method in successive approximation analog-to-digital converter

Abstract

The invention discloses a capacitor array logic control method in a successive approximation analog-to-digital converter, and belongs to the technical field of an analog integrated circuit design. Themethod is a design method of switching logic of a differential capacitor array. According to the method, a capacitor array can access and use the least capacitors in each judgment so that the least non-ideal factors such as mismatch are introduced. Compared with a traditional method and numerous power consumption improvement methods, the method has the advantages that under the condition that thebasic structure of the successive approximation analog-to-digital conversion circuit is not modified, linearity of the successive approximation analog-to-digital converter is improved, and main performance parameters such as an SNDR (Signal to Noise Distortion Ratio) and an SFDR (Dynamic Range) are obviously improved; and subsequent analog or digital calibration of the high-order high-precision successive approximation analog-to-digital converter is facilitated so that overall performance of the converter is improved. Moreover, the method has universality and is suitable for the successive approximation analog-to-digital conversion circuits of most differential capacitor array structures.

Description

technical field [0001] The invention belongs to the technical field of analog integrated circuits, and in particular relates to a capacitor array logic control technology of a differential capacitive successive approximation analog-to-digital converter. Background technique [0002] Capacitive DAC is currently the most important design solution for successive approximation analog-to-digital converters. Among them, the manufacturing accuracy and matching degree of the semiconductor process of the capacitor are the most important factors affecting the accuracy of the analog-to-digital converter circuit. In the actual manufactured analog-to-digital converter circuit, due to the influence of parasitic capacitance and the limitation of semiconductor manufacturing process technology, the capacitance value of the actually produced capacitor cannot be the ideal capacitance value envisioned in the design, and the capacitance of each bit It is impossible to perfectly match the binary...

AI Technical Summary

Problems solved by technology

The existing switch logic control methods hardly have a good performance in solving the problem of capacitance mismatch. Therefore, the present invention makes improvements to this part

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