A Digitally Controlled Op-Amp with Level-Crossing-Based Approximation and its Application to a 10-bit Pipeline ADC

作者：Jee Dong Woo^*; Suh Yunjae; Park Hong June; Sim Jae Yoon

来源：Journal of Circuits, Systems, and Computers, 2016, 25(12): 1650155.

DOI：10.1142/S0218126616501553

• Digital amplifier
• zero-crossing
• level-crossing
• pipeline ADC

A digitally controlled operational amplifier (op-amp) with level-crossing-based approximation is proposed. A high gain is effectively obtained by means of a damping control without a stability problem occurring in the multiple gain stages. Compared to the previous version of the zero-crossing-based algorithmic approximation, the proposed scheme further improves the settling time with the class AB operation obtained by switching of multiple driving paths. For verification, the designed op-amp is applied to a 10-bit pipeline ADC and implemented in a 0.18 mu m CMOS technology. Measured results show that the designed op-amp successfully operates at 10-bit resolution, 10 MSample/s pipeline ADC and achieves an effective gain of more than 60 dB.

• 出版日期2016-12