摘要
A bandgap voltage reference is presented with a piecewise linear compensating circuit in order to reduce the temperature coefficient.The basic principle is to divide the whole operating temperature range into some sub ranges.At different temperature sub ranges the bandgap reference can be compensated by different linear functions.Since the temperature sub range is much narrower than the whole range,the compensation error can be reduced significantly.Theoretically,the precision can be improved unlimitedly if the sub ranges are narrow enough.In the given example,with only three temperature sub ranges,the temperature coefficient of a conventional bandgap reference drops from 1 5×10 -5 /℃ to 2×10 -6 /℃ over the -40℃ to 120℃ temperature range.
提出了一种采用分段线性补偿的方法来实现高精度带隙基准 ,其基本原理是将整个温度区间分为若干个子区间 ,在不同子区间上采用不同线性补偿函数达到最佳补偿 .由于温度区间缩小 ,补偿误差也随之减小 ,从而在整个工作温度区间上的补偿误差也缩小 .理论上 ,只要温度子区间取得足够小 ,就可以达到任意精度 .示例中将 - 4 0～ 1 2 0℃的温度区间仅分为三个子区间 ,平均温度系数就从 1 .5× 1 0 - 5/℃减小到 2× 1 0 - 6 /℃ .
