基于恒流二极管的低压低功耗运算放大器研究

发布时间：2018-11-17 10:48

【摘要】：伴随平板电脑,手机等其他各种移动电子设备的普及,以电池作为电源的微电子产品得到广泛使用,但以电池作为电源的电子产品迫切需要采用低电流低电压的模拟电路来降低功耗。JEFT与双极型器件相结合,已成为新型专用集成运算放大器的主要发展方向之一。本论文研究正是在此背景下,对通用集成运放从另一设计思路创新,提出基于恒流二极管(CRD)的运算放大器。本文设计以JEFT构成恒流二级管(CRD),首先研究其恒流特性,分别对此恒流二极管的恒流值、开启电压、击穿电压、温度特性进行研究,然后再对恒流二极管和双极型晶体管工艺兼容进行研究与设计,最后再对传统集成运放中具有恒流功能和有源负载电流源的双极型器件(BJT)进行替代,并对电路结构进行优化,以减少芯片中元器件个数,从而减小芯片面积,降低静态工作电流以实现更进一步的低功耗。仿真结果表明,当电源电压改变时,双极型运算放大器输入级电流在0.290mA到0.433mA变化,而基于CRD的差分输入级电流约降低一半,电流恒定在0.239mA到0.244mA之间,并且电流变化只有0.005mA。当电源电压恒定在13V时,双极型集成运算放大器偏置电流达到0.739mA,是基于CRD的运算放大器偏置电路电流0.222mA的3倍以上。由此可知,基于CRD的运算放大器能实现更低静态电流。
[Abstract]:With the popularity of tablet computers, mobile phones and other mobile electronic devices, microelectronics, which use batteries as power sources, have been widely used. However, the electronic products with battery as the power supply urgently need to use low current and low voltage analog circuit to reduce power consumption. The combination of JEFT and bipolar devices has become one of the main development directions of new special integrated operational amplifiers. Under this background, this paper proposes an operational amplifier based on constant current diode (CRD) by innovating the general integrated operational amplifier from another design idea. In this paper, the constant current characteristic of the constant current diode (CRD),) is studied by using JEFT as the structure of the constant current secondary transistor. The constant current value, the open voltage, the breakdown voltage and the temperature characteristic of the constant current diode are studied respectively. Then the process compatibility of constant current diode and bipolar transistor is studied and designed. Finally, the bipolar device (BJT) which has constant current function and active load current source in traditional integrated operational amplifier is replaced. The circuit structure is optimized to reduce the number of components in the chip, reduce the chip area and reduce the static working current to achieve further low power consumption. The simulation results show that when the supply voltage changes, the input stage current of bipolar operational amplifier changes from 0.290mA to 0.433mA, while the differential input stage current based on CRD is reduced by about half, and the current is constant between 0.239mA and 0.244mA. And the current changes only 0.005mA. When the supply voltage is constant at 13 V, the bias current of the bipolar integrated operational amplifier reaches 0.739 Ma, which is more than 3 times of the current 0.222mA of the operational amplifier bias circuit based on CRD. Therefore, the operational amplifier based on CRD can achieve lower static current.
【学位授予单位】：贵州大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TN722.77

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