基于Howland电流源产生更优线性度三角波的设计

Design of a Better Linearity Triangle Wave Generator Based on Howland

针对三角波发生器性能的改善,按照对方波电流进行积分的拓扑结构,设计了一种基于方波电压控制的Howland电流源积分电路。理论分析验证了设计的正确性,证明了产生波形为线性对称三角波。实验结果表明,Howland电流源恒流误差小于微安级,产生三角波较常用发生器在测试频段内具有最小二乘评价法下更优的线性度和对称性,且频率和幅值均可灵活地进行调节。实现方法结构简单、硬件开销小、产生波形标准、具有很好的应用价值。

Aiming at improving the performance of triangle wave generators, an integrated circuit design based on the Howland current source which is controlled by a square voltage signal is proposed according to the topology of the integration of a square wave current source. Theoretic analysis proves the validity of the design and the linearity and symmetry of the wave generated. Experimental results show that the error of the constant-current characteristic is beneath microampere level and the triangle wave enjoys a better linearity and symmetry in an entire test waveband compared to that of a common signal generator under the least square measurement method, and the frequency and amplitude can be adjusted conveniently. This implementation method has a simple structure, low hardware overheads, desirable applications, and has generated standard waveforms.