基于TMS320F28335高精度串行A/D和D/A转换芯片的接口设计与实现  

Design and implementation of high- precision serial A/D and D/A converter chips interface based on TMS320F28335

作　　者：李冬梅[1] 胡睿[1] 

机构地区：[1]清华大学精密仪器系,北京100084

出　　处：《自动化与仪器仪表》2016年第10期82-84,共3页Automation & Instrumentation

基　　金：国家重大仪器设备开发专项(2013YQ310737)

摘　　要：为了实现多通道高精度控制电压的输入输出,以TMS320F28335为核心,采用18位串行高精度A/D芯片AD7690和16位串行高精度的D/A芯片AD5668来分别实现A/D和D/A转换,AD7690和AD5668的时钟输入和数据接口直接与DSP的SPI(串行外设接口)时钟和数据引脚相连,使用CPLD控制A/D、D/A芯片和DSP的接口逻辑。后续的系统调试验证表明:AD7690能够通过SPI实现数据的传入,经过最小二乘拟合校正后误差变为原来的1/10左右;AD5668可以通过SPI实现电压的输出,经过最小二乘拟合校正输出精度±0.5m V以内,满足了系统要求。In order to achieve the input and output of multi-channel and high-precision control voltage.Based on TMS320F28335,respectively use 18 bit serial high precision A / D chip AD7690 and 16 bit serial high precision D / A chip AD5668 to realize D / A and A / D conversion,clock input and data interface of AD7690 and AD5668 are directly connected to the SPI clock and data pin of DSP,CPLD is used to set the interface logic of the A / D,D / A and DSP chips.Subsequent system debugging verified and showed that the AD7690 data input can be realized through SPI,after least square fitting correction,the error decreased to about 1 / 10 of the original; AD5668 voltage output can also be realized through the SPI,after least square fitting g correction,accuracy of the output voltage is within ± 0. 5 m V,satisfied the system requirements.

关 键 词：TMS320F28335 串行外设接口 AD7690 AD5668 最小二乘拟合校正 

分 类 号：TP368.1[自动化与计算机技术—计算机系统结构]