一阶巴特沃斯高通滤波器电路图(First-Order Butterworth High-Pass Filter)
图1. 一阶巴特沃斯高通滤波器电路图
上图是一由通用运放(如741,351等)组成的一阶巴特沃斯高通滤波器电路。截止率由RC确定，fc = 1/{2π(RC)}.增益Gp = 1 + (RF/R1)。
The circuit shown in Figure 1 is a first-order Butterworth high-pass filter. A high-pass filter is a circuit that blocks signals with frequencies lower than a cut-off frequency fc. The circuit in Figure 1 uses an op-amp configured as a non-inverting amplifier, with an RC circuit at the non-inverting input to do the filtering of the low-frequency signals. The cut-off frequency fc of this circuit is determined by R and C, i.e., fc = 1/{2π(RC)}.
The pass-band gain Gp of this filter is given by: Gp = 1 + (RF/R1). Thus, if the frequency f of the input signal is higher than fc, Vo ≈ Gp x Vin. If f = fc, Vo ≈ 0.707 Gp x Vin. If f < fc, Vo < Gp x Vin.