带内噪声整形连续时间滤波器

In-Band Noise Shaping Continuous Time Filter

提出了一种带内噪声整形连续时间滤波器,详细分析了滤波器的传输特性和噪声整形原理。采用0.18μm CMOS工艺,设计了一个4阶巴特沃斯型全差分低通滤波器。仿真结果表明,滤波器的带内增益为10 dB,-3 dB频率为4.5 MHz;输出噪声的理论分析与仿真结果一致;在2.5V电源电压下,消耗电流为0.8 mA,带外IIP3为25.3 dBV,带外无杂散动态范围为65.3 dB。

An in-band noise shaping continuous time filter was proposed.Transfer characteristics and principle of noise shaping were described in detail.A 4th-order Butterworth fully differential low-pass filter was designed in CMOS 0.18 μm technology.Simulation results showed that the filter had an in-band gain of 10 dB and a-3 dB frequency of 4.5 MHz,and theoretically calculated output noise was consistent with simulated results.Operating at 2.5 V supply voltage,the circuit consumes 0.8 mA of current.And out-band IIP3 of 25.3 dBV and out-band SFDR of 65.3 dB were achieved.