一种时间交叉采样ADC失调与增益误差校准方案

Calibration of Offset and Gain Mismatches in Time-Interleaved AD Converters

针对时间交叉采样模数转换器的失调、增益误差提出了校准方案.该方案主要通过各通道模数转换器向同一通道校准的方法,首先计算出误差参数,再根据误差参数对数字量进行校准.采用该校准方案对四通道10位640Msps模数转换器进行校准,经MATLAB仿真,结果表明输入频率为79.14MHz时,校准后的无杂散动态范围为75.17dB,信噪比为55.98dB,有效精度为9.01bit,比较准前分别提高了24.6dB、6.47dB、1.08bit.

A new scheme is presented to eliminate the errors resulted from offset and gain mismatches in time-interleaved ADCs. Firstly, the mismatch parameters of all of the channels relative to one same channel are calculated, and then, the output data of the channels are adjusted according to the mismatch parameters. The MATLAB simulated results show that for a 79. 14 MHz sinusoidal input, a 4-channel 10 bit 640 Msps ADC achieves a SFDR of 75.17dB, a SNR of 55.98 dB, and an ENOB of 9.01 bit after calibration, respectively 24. 6 dB,6.47 dB,1.08 bit higher than those before calibration.