A background calibration technique for time-interleaved analogue-to-digital converter (TIADC) over Sub-Nyquist frequency timing mismatch is proposed. When the input signal only satisfies the Nyquist sampling theorem of the overall TIADC rather than sub-ADC, both directions of estimation based on correlation and compensation based on differentiator may be opposite to the actual value, which results in a failure calibration. In this Letter, the authors propose a calibration direction correction algorithm which can detect and correct the calibration direction and assure an effective calibration in the whole Nyquist frequency of TIADC. Simulation results show that, for a four-channel 12-bit 1 GS/s TIADC, with f in / f s = 0.45 , signal to noise and distortion ratio (SNDR) is improved from 30.1 to 73.2 dB.

中文翻译：

---

奈奎斯特频段TIADC的背景时序失配校准技术

提出了一种基于亚奈奎斯特频率时序失配的时间交错模数转换器(TIADC)的背景校准技术。当输入信号仅满足整个TIADC而非子ADC的奈奎斯特采样定理时，基于相关的估计和基于微分器的补偿的两个方向都可能与实际值相反，从而导致校准失败。在这封信中，作者提出了一种校准方向校正算法，该算法可以检测和校正校准方向，确保在 TIADC 的整个奈奎斯特频率上进行有效校准。仿真结果表明，对于四通道 12 位 1 GS/s TIADC，当 f in / fs = 0.45 时，信噪比（SNDR）从 30.1 dB 提高到 73.2 dB。