一种GPS校准的数字式高精度守时钟  

GPS disciplined precise digital timekeeping clock

作　　者：魏丰[1] 朱广伟[1] 王瑞清[1] 王群 

机构地区：[1]华中科技大学控制科学与工程系 [2]解放军94921部队

出　　处：《仪器仪表学报》2011年第4期920-926,共7页Chinese Journal of Scientific Instrument

摘　　要：晶振老化是影响时钟守时精度的最主要原因,一般的解决方法是采用GPS校准锁相环微调压控晶振的振荡周期进行补偿的电路方案。介绍了一种由固定频率晶振驱动的分频比可精细微调的基于加法器的时钟电路。提出了一种新颖的基于该时钟电路,采用GPS接收机、单片机、可编程逻辑器件和TDC构成的全数字化守时钟电路方案。该方案具有守时精度高、全数字化设计、简单和便于集成等优点,特别适合于只校时不锁频场合。最后以一个守时精度为1毫秒/日的守时钟为例说明了该电路的设计方法和步骤,给出了实测结果。Aging of crystal oscillator is a main factor influencing the accuracy of clock.Compensation is usually achieved by slightly changing the oscillation cycle of the crystal.An adder-based clock circuit,whose frequency dividing ratio can be adjusted fine and smoothly,is introduced in this paper.A novel circuit scheme of GPS disciplined timekeeping clock is presented,which consists of adder-based clock,GPS receiver,MCU,CPLD and TDC.The circuit scheme has the advantages of high precision,fully digitized design,simple structure and convenient to be integrated,which is especially suitable for the situations where only time correction and but no frequency locking are needed.As an example,the design procedure and practical test result of a clock with timekeeping precision of 1ms/day in holdover mode are given.

关 键 词：基于加法器的时钟 守时 卫星全球定位系统 时间数字转换器 

分 类 号：TP393[自动化与计算机技术—计算机应用技术]