Input feedforward type Delta-Sigma modulator

Abstract

The invention belongs to the technical field of integrated circuits of data converters, and particularly relates to an input feedforward type Delta-Sigma modulator. The modulator comprises a system level part and a circuit level part, wherein in the system level part, the traditional modulator is used as a prototype of the modulator, and semi-cycle delay is separated from a loop filter through equivalent transformation and transferred to a direct input path and a feedback path, so that the semi-cycle delay on the direct input path shares a clock phase with feedforward simulation summation, quantization and dynamic element matching of a feedback loop, and sequence constraints are further loosened; in the circuit level part, an input network is established by a first integrator of the loop filter through an advance sampling capacitor, a re-sampling capacitor and switches, input signal sampling and the semi-cycle delay are achieved through voltage-doubling sampling / charge redistribution, and feedback is carried out through the re-sampling capacitor so that the feedback path is kept unchanged and quantizing noise is prevented from being folded. The modulator provided by the invention has the advantage that analog-digital conversion with low power consumption and high accuracy can be achieved.

Description

technical field [0001] The invention belongs to the technical field of data converter integrated circuits, and in particular relates to an input feedforward Delta-Sigma modulator applied to a Delta-Sigma analog / digital converter. Background technique [0002] In today's data-driven society, the analog-to-digital converter (ADC) plays an important role. With the rapid development of electronic technology, it has been widely used in military detection, industrial instruments, communication systems, medical electronics, and consumer electronics. widely used. Delta-Sigma (DS, Δ-Σ) ADC is one of the three mainstream ADC architectures, and the DS modulator is the core component of DS ADC. [0003] With the continuous shrinking of CMOS technology feature size, the intrinsic gain of MOS transistors gradually decreases, and it becomes more and more difficult to construct high-precision analog circuits. However, thanks to oversampling and noise shaping techniques, the performance of ...

AI Technical Summary

Problems solved by technology

[0017] In order to solve the timing constraint problem of the input feedforward DS modulator and overcome the deficiencies of the existing solutions, the present invention provides an input feedforward Delta-Sigma modulator, which can not only relax the timing constraint of the modulator, but also can keep the modulator in good condition

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