Analog-to-Digital Converter Front-End Circuit

Abstract

The invention provides a front-end circuit of an analog-digital converter, comprising an MDAC (Multiple Digital-to-Analog Converter) branch circuit and an ADC (Analog-to-Digital Converter) branch circuit, wherein the MDAC branch circuit is used for receiving input voltage Vin and outputting residual voltage Vout; the ADC branch circuit is used for receiving the input voltage Vin and outputting an A / D (Analog / Digital) conversion result Dout. The aperture error of the circuit can be reduced on the basis of not increasing a clock phase, a dynamic comparator is adopted, a direct current through circuit does not exist in the circuit during working, and the power consumption of the system is reduced.

Description

technical field [0001] The invention belongs to the technical field of analog-to-digital conversion, and in particular relates to a front-end circuit of an analog-to-digital converter. Background technique [0002] With the rapid development of the new generation of wireless communication technology, the system puts forward higher requirements on the power consumption and information processing capability of the analog-to-digital converter. Therefore, high speed, high precision and low power consumption have become the main trends in the development of ADC (Analog-to-Digital Converter, analog-to-digital converter). Considering these three factors comprehensively, the pipeline structure becomes the best choice. The traditional pipeline ADC is mainly composed of input sampling and holding amplifier, stage conversion circuit, clock circuit and reference circuit. Among them, the input sample-and-hold amplifier is in the first stage of analog signal processing, its power consump...

AI Technical Summary

Problems solved by technology

However, when the sampling is tracked with respect to the input voltage, the signal path of the MDAC is a passive RC network composed of switches and sampling capacitors, while the signal path in the sub-ADC is an active tracking amplification network composed of switches, capacitors, and preamplifiers , the two signal paths are of different types and are mismatched in nature. This mismatch will bring aperture error. The higher the input voltage frequency, the larger the aperture error, which will limit the input bandwidth of the entire ADC.

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