Charge pump and voltage controlled-oscillator-based oversampling analog-digital converter

Abstract

The invention discloses a charge pump and voltage controlled-oscillator-based oversampling analog-digital converter. The charge pump and voltage controlled-oscillator-based oversampling analog-digital converter comprises a first asynchronous pulse width modulator, a charge pump, a second asynchronous pulse width modulator, a voltage-controlled oscillator quantizer and a analog-digital converter, wherein the first asynchronous pulse width modulator, the charge pump, the second asynchronous pulse width modulator and the voltage-controlled oscillator quantizer are sequentially connected with a forward-direction channel, and the analog-digital converter is connected with a feedback channel; analog signals converted by the analog-digital converter are subtracted from the output signals of the first asynchronous pulse width modulator and the output signals of the charge pump respectively, so that error signals can be obtained and are transmitted to the charge pump and the second asynchronous pulse width modulator, and therefore, a closed loop system can be formed. According to the charge pump and voltage controlled-oscillator-based oversampling analog-digital converter, a simple and low-power consumption structure is adopted to replace a complexly-structured and high-power consumption analog integrator, and higher accuracy can be obtained.

Description

technical field [0001] The invention relates to the field of analog circuits and mixed signal circuits, in particular to an over-sampling analog-to-digital converter based on a charge pump and a voltage-controlled oscillator. Background technique [0002] In the wireless communication front-end circuit, the analog-to-digital converter (ADC) is an important module, which is responsible for converting the analog signal output by the RF front-end circuit into a digital signal and passing it to the subsequent digital back-end for signal processing. The indicators to measure the analog-to-digital converter mainly include bandwidth (speed), precision and power consumption. The oversampling analog-to-digital converter is an important structure in the analog-to-digital converter, which is composed of a loop filter, a quantizer and a feedback digital-to-analog converter. In recent years, its application has expanded from the audio field to the communication field. Compared with othe...

AI Technical Summary

Problems solved by technology

This makes the analog-to-digital converters face the following problems: First, the voltage space available for signals in the circuit is getting smaller and smaller, and the signal amplitude is getting smaller and smaller. The on-resistance and nonlinearity of the switch in the switched capacitor circuit will be increase

Second, the intrinsic gain of the amplifier will decrease, and many techniques to increase the gain of the amplifier cannot be applied to the design of the amplifier due to the limitation of the power supply voltage

The output of the quantizer has intrinsic dynamic element matching, which greatly reduces the matching requirements of the feedback DAC

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