A 14-Bit 2GS/s and 12-Bit 4GS/s Reconfigurable DAC with Triple Modes

  • 翁 聖洋

Student thesis: Master's Thesis


In this thesis a triple-mode 14-bit 2GS/s or 12-bit 4GS/s reconfigurable current-steering digital-to-analog converter (DAC) is presented For different DAC applications triple mode is proposed which means over-sampling mode Nyquist mode and over-Nyquist mode The target of this work is that using a single DAC chip to fulfill all of the applications and with better performances than any state-of-the-art work For this target many techniques are proposed to improve the performances In current-steering DAC design current source mismatch is a main problem Minimum switching dynamic element matching (MSDEM) and data weighted averaging (DWA) are adopted to process the harmonic distortion caused by mismatch In addition for over-sampling mode DWA is used to improve the performance in narrow band Moreover for over-Nyquist mode a novel method is proposed which makes the signal consumption <10dB and spurious-free dynamic range (SFDR) > 65 dB up to 3rd Nyquist band The current-steering DAC is fabricated in TSMC 90nm 1P9M CMOS technology with only 0 082mm2 of active area The measurement results show that the DAC achieves >60dB SFDR from dc to 0 55GHz at 1 1GS/s and the 14-bit Nyquist band performance is the best in figure of merit (FOM) comparing to state-of-the-art works
Date of Award2014 Aug 6
Original languageEnglish
SupervisorTai-Haur Kuo (Supervisor)

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