基于自由环振和飞加法器结构的时域数字控制振荡器

A time-domain digitally controlled oscillator （DCO） is proposed. The DCO is composed of a free-running ring oscillator （FRO） and a two lap-selectors integrated flying-adder （FA）. With a coiled cell array which allows uniform loading capacitances of the delay cells, the FRO produces 32 outputs with consistent tap spacing for the FA as reference clocks. The FA uses the outputs from the FRO to generate the output of the DCO according to the control number, resulting in a linear dependence of the output period, instead of the frequency on the digital controlling word input. Thus the proposed DCO ensures a good conversion linearity in a time-domain, and is suitable for time-domain all-digital phase locked loop applications. The DCO was implemented in a standard 0.13μm digital logic CMOS process. The measurement results show that the DCO has a linear and monotonic tuning curve with gain variation of less than 10%, and a very low root mean square period jitter of 9.3 ps in the output clocks. The DCO works well at supply voltages ranging from 0.6 to 1.2 V, and consumes 4 mW of power with 500 MHz frequency output at 1.2 V supply voltage.     

DVI接口及物理层一致性测试

数字视频接口(DVI)正越来越广泛的应用于计算机和消费电子产品上作为其视频接口,它是基于TMDS(Transition Minimized Differential Signaling,转换最小差分信号)技术来传输数字信号,DVI包括一个传送器和一个接收器。文中主要介绍DVI接口并对物理层进行一致性测试。     

盘式电机定转子铁芯冲卷设备控制系统设计

盘式电机具有结构紧凑、轴向尺寸短、制动力矩大、制动迅速、定位准确等优点。但定子和转子的卷铁心制造难度大是制约其应用的主要原因。本文通过对盘式电机定转子铁心的槽位置的分析,建立一个数学模型,设计由单片机、传感器、步进电机及驱动器构成的控制系统,通过对步进电机的变角度控制,实现带料的变距送料,进而实现槽间距的准确控制。冲完...