一种正反馈摆率增强运算跨导放大器  

A Positive Feedback Slew-Rate Enhanced OTA

作　　者：张飞翔[1] 万宵鹏 甄少伟[1] 张有润[1] 罗萍[1] 张波[1] 

机构地区：[1]电子科技大学电子薄膜与集成器件国家重点实验室,成都610054

出　　处：《微电子学》2015年第3期281-284,289,共5页Microelectronics

基　　金：国家自然科学基金资助项目(61274027);模拟集成电路重点实验室基金资助项目(9140C090503140C09045)

摘　　要：提出一种正反馈摆率增强运算跨导放大器(OTA),采用共栅输入结构,利用MOS管自身平方率的I-V特性,突破了尾电流对OTA摆率的限制。输入级采用局部正反馈结构,进一步增强了OTA的摆率,电路的增益带宽积也有所提高。基于0.5μm CMOS工艺,5V单电源供电,在静态功耗为150μW,负载电容为10pF的情况下,正向摆率与负向摆率分别为61.1V/μs与23.2V/μs,低频增益为47.6dB,单位增益带宽达到3.62 MHz。在静态电流相同的情况下,提出的摆率增强OTA与传统OTA电路相比,CBF+增大22.2倍,CBF-增大8.3倍。A positive feedback slew-rate enhanced operational transconductance amplifier （PFB-SRE OTA） was presented. The input stage was common-gate structure, taking advantages of the square ratio of the I-V characteristic of MOS, so the SR limit of bias current of OTA could be eliminated. Furthermore, the local positive feedback in input stage could enhance SR and improve the gain bandwidth product（GBW）. The circuit was designed in 0.5 μm CMOS process. Under a 5 V power supply, the simulation result showed that 61.1 V/μs positive slew- rate and 23.2 V/μs negative slew-rate were achievable for a load capacitance of 10 pF with 150 μW static power consumption. In addition, the voltage gain was 47.6 dB, and the unit gain bandwidth was 3.62 MHz. Compared with the traditional OTA, CBF＋ and CBF- of the proposed OTA increased 22.2 and 8.3 times respectively.

关 键 词：运算跨导放大器 正反馈 摆率增强 

分 类 号：TN432[电子电信—微电子学与固体电子学]