应用中使用了ADS1254 AD芯片,VREF= 5 V
CH1- 接2.5V
CH1+ 介于0V–5V之间
当CH1+ 大于 CH1-时,AD采样结果正确无误,但是当CH1+ 小于CH1-时,AD采样结果却不对了,且无论我怎么改变CH1+的电压,只要是CH1+小于CH1-,
采样结果基本不变,如下所示?
EnvTemp = 23.07,AdCode = 07 e5 3f AdValue = 0.308
EnvTemp = 23.07,AdCode = 07 e4 a9 AdValue = 0.308
EnvTemp = 23.07,AdCode = 07 e5 69 AdValue = 0.308
EnvTemp = 22.91,AdCode = 07 e4 c3 AdValue = 0.308
EnvTemp = 23.48,AdCode = 07 e4 92 AdValue = 0.308
EnvTemp = 23.48,AdCode = 07 e4 73 AdValue = 0.308
EnvTemp = 22.99,AdCode = 07 e4 f8 AdValue = 0.308
EnvTemp = 22.99,AdCode = 07 e5 38 AdValue = 0.308
采样结果居然是一个0.31V 左右的值?
不解,请各位朋友帮忙分析分析。谢谢
user151383853:
CH1+ 低于 CH1-, 将是负值, 数据格式发生了变化, 注意一下哦
user1350908:
回复 user151383853:
看上边我贴出来的部分数据,AD码值符号位明显没有置1,还是一个正值,但是此时CH1+ 确定是小于CH1-