一种利用体偏置改善温度特性的电流源

A Current Reference Utilizing Body Bias to Improve Temperature Characteristic

基于130 nm绝缘体上硅工艺技术,针对工艺偏差对器件特性带来的影响,提出了一种可跟随工艺偏差自动调整温度系数的电流源;针对交叉耦合电流镜,引入自适应体偏置电路来改善电路在不同工艺角下的温度系数;仿真结果表明:-40~85℃温度范围内,工艺偏差使得所提电流源温度系数偏离典型工艺角下的值为22%,而无体偏置电流源偏离达100%之多,所提电流源在不同工艺角下平均温度系数为91 ppm/℃,比无体偏置电流源温度系数降低50%。

Based on the Si technology on the 130 nm insulator,according to the influence of process deviation on device characteristics,a current reference that can automatically adjust the temperature coefficient following process deviation is proposed.The proposed current reference circuit is based on a cross-coupled current mirror and employs auto-adaptive body bias technique to improve temperature coefficient under different process corners.The simulation result shows that process deviation makes the temperature coefficient of the proposed current reference deviate from the value of typical process corner by 22% over the temperature range from -40℃ to 85℃,while the current reference without body bias deviates by as much as 100%.The proposed current reference has an average temperature coefficient of 91 ppm/℃ at difference processes,which is 50% lower than that of the current reference without body bias.