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关于ADS8688的问题求助!!!谢谢大神们啦

Other Parts Discussed in Thread: ADS8688, ADS8698

1、ADS8688(16 bits)数据手册中给了一个PLC与ADS8688结合的测试例程,16-Bit, 8-Channel, Integrated Analog Input Module for Programmable Logic Controllers (PLCs)(TIDU365)(地址www.ti.com/.../TIDA-00164),在文件Test Data中7.2节的Accuracy Test Results中FSR Error是怎么计算的?

2、ADS8688(16 bits)例程中提到精度为0.2%,而ADS8698(18bits)的数据手册中提到的精度也是0.2%,为什么分辨率高了精度还是一样啊?

  • 因为分辨率和精度不是相同的概念。精度是ADC采样后的值和理想电压值的误差,分辨率是最小能够分辨的电压值。

    ADC输出 = 2^N(Vin/VREF). N为ADC分辨率。参考对ADC转换后的值的精度是有直接影响的,你可以看看这两颗芯片内部参考的精度,从参考的精度来说,这两个芯片的精度几乎是相同的。即使ADS8698分辨率更高。