本文实现了一个应用于全集成L带DAB接收机的5阶Gm-C椭圆低通滤波器,该滤波器上集成了基于锁相环的片上频率自动调谐电路,使得该滤波器的截止频率可以准确控制在4MHz.该滤波器已经采用0.35mCMOS工艺实现.测试结果表明,该滤波器的频率精度可以控制在1%以内,动态范围约为54dB,阻带抑制率大于40dB,该滤波器采用3.3V电源,消耗的电流约为13mA.
A fifth-order elliptic low-pass Gm-C filter used in monolithic DAB receiver is presented. The filter integrates an on-chip frequency automatic tuning circuit based on PLL to control the cutoff frequency. The filter has been implemented in 0.359m CMOS process. The measurement results show that the frequency tuning error is within 1%, the dynamic range is 54dB, and the stop-band rejection rate is greater than 40dB.The filter draws 13mA current from a 3.3V power supply.