一种用于随机快闪A/D转换器的数字校准算法

Digital Calibration for Stochastic Flash Analog-to-Digital Converter

随机快闪A/D转换器(SF-ADC)的传输函数满足正态分布曲线,线性度较差。对该类型ADC的数字后台校准算法进行研究,提出一种新的校准算法。该算法通过分段逼近结合反函数的方法来校准传输函数的非线性谐波误差,大幅提高了ADC的输入信号范围,从而提高了ADC的信噪比。采用Matlab和Modelsim仿真软件对该算法进行仿真验证,结果显示,提出的校准算法使ADC的输入信号范围拓宽到理论上的最大值(-3σ～+3σ),信噪比达到42.54dB。

Transfer function of stochastic flash AI）C （SF-ADC） follows Gaussian distribution with a poor linearity. A novel algorithm was proposed to improve the linearity of SF-ADC. By piecewise approximation and inverse function, the proposed algorithm could calibrate nonlinear harmonic errors of transfer functions and greatly improve input signal range and signal noise ratio （SNR） of the ADC. Simulations were made with Matlab ＆ Modelsim to verify the algorithm. Results indicated that the proposed algorithm extended input signal range and SNR of the ADC to theoretically maximum value （-30σ～＋3σ） and 42.54 dB, respectively.