固定相位关系的正弦波可应用于通信设备、仪器和电源中。虽然可以用多种传统的模拟技术产生基本的正弦波信号,但本设计实例提供了一种简单的方法,它只使用数字逻辑和固定值电阻器(图1a)。一个公共的时钟脉冲驱动一对CD40154位移位寄存器的3/4,寄存器不断循环一个由12个0和12个1组成的样式,即000000000000111111111111。每个寄存器的输出都驱动一个电阻器,即R_1～R_(12),这些电阻器连接到一个汇总 Sine waves with fixed phase relationship can be used in communications equipment, instrumentation and power supplies. Although it is possible to generate basic sinusoidal signals using a variety of conventional analog techniques, this design example provides an easy way to use only digital logic and fixed-value resistors (Figure 1a). A common clock driver drives a pair of CD40154 bit shift registers 3/4, and the register cycles through a pattern of 12 0s and 12 1s, which is 000000000000111111111111. The output of each register drives a resistor, R_1 ~ R_ (12), which are connected to a summary