一种高精度电流镜电路架构的设计

Design of the structure of current mirror of high accuracy

电流镜在模拟电路中是核心模块之一,在模拟电路要求较高的场合,精度是决定电流镜性能的重要参数之一;但随着工艺尺寸的减小,由于沟道长度调制效应,电流镜电流匹配精度变低;采用UMC 65 nm工艺,通过Cadence公司的Spectre进行仿真验证,文章所提出的电流镜电路架构实现了较高的精度,使得随着工艺尺寸的减小所带来的偏差能够很大程度减小,满足了电路对高精度的要求。

The current mirror is one of the key elements in analog circuit design. In order to get better performance of analog circuits, the accuracy of the current mirror, which is one of the most important parameters, has to be assured. But with model dimension reducing, the match accuracy of current mirror＇s current becomes lower because of the channel length modulation effect. In this paper, the structure of a current mirror is put forth ＇and simulated and verified by employing the model of UMC 65 nm and the Cadence＇s Spectre. The presented structure achieves higher accuracy and makes the partial difference due to model dimension reducing reduce to a large extent, and the demand of the circuit for high accuracy is met.