基于CPLD的数字电压表设计

Desing of Digital Voltmeter Based on CPLD

双积分型ADC具有转换精度高,速度慢的特点,因而被广泛应用于高精度数字仪器仪表中。该设计的主要创新点是以可编程器件(CPLD)为核心,采用积分电路、检零比较器等组成16位ADC,控制部分采用51单片机,能实现自动量程转换。由于采用了CPLD技术,减少了外界干扰和所占空间,而且大大提高了系统的响应时间,提高了数字电压表的性能。

Since the double integral type of ADC takes on the characteristics of high conversion accuracy and slow speedt,it is widely used in the high-precision digital instruments.The double integral electro circuit,zero-checking comparator and FPGA are adopted in the design to makeup the 16 bit ADC.AT80C51 single chip computer is used in the control section,which is also able to compare zero automatically and carry the transform of capacity rules.Because the interferes from outside and the space occupied by electro circuits are reduced through the employment of FPGA technology,the system response time and the performance of digital voltmeter are improved enormously.