Sigma-Delta modulator based on VCO quantizer

Abstract

The invention discloses a Sigma-based on a VCO quantizer. The Delta modulator comprises a VCO quantization module (1), a feedback module (2), an input capacitor C and an input resistor R, wherein theVCO quantization module (1) is connected with an input end VIN through the input capacitor C and is used for receiving and quantifying an input signal and outputting a digital signal; the input end ofthe feedback module (2) is connected with the output end of the VCO quantization module (1), and the output end of the feedback module (2) is connected with the input end of the VCO quantization module (1) and used for feeding back an output code of the VCO quantization module (1) to the input end; and one end of the input resistor R is connected between the input capacitor C and the VCO quantization module (1), and the other end of the input resistor R is connected with a VCM level. According to the Sigma-Delta modulator based on the VCO quantizer, provided by the invention, the VCO is combined with the Sigma-Delta ADC, VCO is used as a quantizer, low power supply voltage work is achieved, meanwhile, a Sigma-Delta modulator structure is adopted, the system structure is simplified, powerconsumption and the area are reduced, and good performance of the circuit is guaranteed.

Description

technical field [0001] The invention belongs to the technical field of electronic circuits, and in particular relates to a Sigma-Delta modulator based on a VCO quantizer. Background technique [0002] Analog-to-Digital Converter (ADC) refers to a device that converts continuously changing analog signals into discrete digital signals, and plays a very important role in signal processing. The traditional ADC completes digital quantization by comparing the analog input voltage with the reference voltage in the voltage domain, and its ability to distinguish the input voltage determines the performance of the ADC circuit. With the advancement of semiconductor technology, the chip power supply voltage continues to decrease, which brings many problems to the design of traditional analog circuits, such as the reduction of input and output voltage swings, the deterioration of linearity, and the voltage corresponding to a conversion step when the number of bits is the same. At the sa...

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Problems solved by technology

With the advancement of semiconductor technology, the chip power supply voltage continues to decrease, which brings many problems to the design of traditional analog circuits, such as the reduction of input and output voltage swings, the deterioration of linearity, and the voltage corresponding to a conversion step when the number of bits is the same. At the same time, limited by the comparison accuracy of the comparator, it becomes very difficult to directly complete the quantization of the analog input voltage, which undoubtedly increases the difficulty of ADC design.

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