基于数字锁相环在汽车MP3无线发射器的应用设计

Application Design of Wireless Launcher in Automobile MP3 Based on Digital Phase-Lock Link

介绍了数字锁相环在汽车MP3无线发射器应用设计技术,讲述数字锁相环的设计思路,着重介绍了PLL频率合成电路、前置分频器、鉴频器/鉴相器、环路滤波器设计方法、稳频技术。通过单片机控制,实现频率自动跟踪锁定,中心频率稳定度达到预定的要求,发射频率数字化控制,性能指标达到较高的水平,输出信噪比大于50db。

This article introduces the application design technology of wireless launcher with digital phase-lock link in automobile MP3, narrates the design idea of numeral phase-lock link, mainly introduces the PLL frequency synthesis electric circuit, the preposed frequency divider, the discriminator emphatically/discriminator, ring circuit filter design method and the steady frequency technology. Through the monolithic integrated circuit control, it realizes the frequency automatic track locking; achieves the expected request for center frequency stability, the digital control of transmitting frequency reaches a higher level with its function aim; the output signal to noise ratio is bigger than 50db.