全差分超级自适应偏置跨导运算放大器

A Fully Differential Super Self-Biasing Operational Transconductance Amplifier

介绍了一种低电压、高效率的全差分自适应偏置跨导运算放大器。采用甲乙类的差分结构作为输入级,包含一个本地共模反馈结构(LCMFB),用以提供额外的电流自举,同时也提高其增益带宽积(GBW)和达到近乎理想的电流效率。采用TSMC 0.25μm标准工艺,实现全差分超级自适应运算放大器。为了比较,同时实现了传统的跨导运放和单端输出超级自适应运放。在10μA偏置电流和2 V工作电压下,与传统结构相比,超级自适应运放的转换速率提升了200倍,增益带宽积提高了4倍;而其全差分结构相对单端结构在几乎所有性能提升一倍的同时,还获得很好的共模抑制比和电源抑制比。

A low-voltage power-efficient fully differential super self-biasing operational transeonductance amplifier （OTA） is presented, in which Class AB differential input stages are combined with a local common-mode feedback structure （LCMFB） for providing additional dynamic current boosting and near-ideal current efficiency as well The circuit is implemented in TSMC＇s 0. 25 μm CMOS technology. A conventional OTA and a single-end output super self-biasing OTA are realized for comparison. For an 80 pF load, super biasing OTAs show enhancement factors up to 200 and 4 for slew rate and GBW, respectively, compared to the conventional OTA with the same 10 μA quiescent current and 2 V supply voltage. The full differential structure maintains good CMRR and PSRR while its GBW and slew rate doubles, compared to the single-output structure.