Successive-approximation-register analog-to-digital converter for programmably amplifying amplitude of input signal and method thereof

Abstract

Disclosed are a successive-approximation-register (SAR) analog-to-digital converter (ADC) for programmably amplifying an amplitude of an input signal and a method thereof. During a sampling phase, a bottom plate of at least one capacitor in a capacitor array is connected electrically to an input signal, so that the capacitor array samples and amplifies the input signal, so as to lower a required sampling capacitor or reduce noise generation.

Description

CROSS-REFERENCES TO RELATED APPLICATIONS[0001]This non-provisional application claims priority under 35 U.S.C. §119(a) on Patent Application No. 201310156698.1 filed in China, P.R.C. on 2013 Apr. 28, the entire contents of which are hereby incorporated by reference.BACKGROUND[0002]1. Technical Field[0003]The present invention relates to a successive-approximation-register (SAR) analog-to-digital converter (ADC), and more particularly, to an SAR ADC for programmably amplifying amplitude of an input signal and a method thereof.[0004]2. Related Art[0005]An analog-to-digital converter (ADC) has multiple architectures, such as a flash ADC, a pipelined ADC and a successive-approximation-register (SAR) ADC. Each architecture has its own advantages and is generally selected according to different application requirements. In comparison with other architectures, the SAR ADC consumes less power, while occupying smaller area and incurring a lower cost.[0006]The operation of the SAR ADC starts ...

AI Technical Summary

Benefits of technology

This approach effectively amplifies the input signal amplitude with reduced noise and smaller capacitors, while automatically converting pseudo-differential signals to full differential signals to suppress power supply and common-mode noise.

Problems solved by technology

In the prior art, a programmable gain amplifier (PGA) is mainly used to amplify the amplitude of the input signal, but the PGA itself occupies the area of a chip, and contributes extra noise.

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