With the development of semiconductor process technology a system on a PCB (Printed Circuit Board) which is composed of several ICs can be integrated into a chip.
随着集成电路工艺的飞速发展，人们已经可以将原先的板级系统集成在一块芯片上，系统芯片逐渐成为集成电路设计的主流发展趋势。
With the development of semiconductor process technology, nowadays a system on a PCB (Printed Circuit Board) which is composed of several ICs can be integrated into a chip.
随着集成电路制造工艺的飞速发展，人们已经可以将原先用各种电路搭建的板极系统集成在一块芯片上。
But PLLs design process involves much theory and application base, such as signal and system, integrated electronics, layout, semiconductor technology, measurement etc.
但是锁相环的设计过程，涉及到信号与系统、集成电子学、版图、半导体工艺和测试等方面，难度比较大。
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