ADS131M08: 技术咨询

Xu Allen

Expert 1045 points

Part Number: ADS131M08

你好，

采用ADS131M08内置的DC源测试，如下图所示，选择DC Test Signal，前四通道选择正电源，后四个通道选择负电源。

Gain设置为1，理论计算按照下图，

理论计算内部参考电压1.2V，用16bit数据对应32768，理论计算得采样值应为2/15*32768=4369；实际采样值为4164，差异比较大，请问是什么原因导致的？

实际采样值入下图所示：

软件配置如下：

//第一通道接正电源测试

    err = writeSingleRegister(CH0_CFG_ADDRESS, CH2_CFG_MUX2_DC_DIAGNOSTIC);
   if(err != 0)return -1;
   //第二通道接正电源测试
   err = writeSingleRegister(CH1_CFG_ADDRESS, CH2_CFG_MUX2_DC_DIAGNOSTIC);
   if(err != 0)return -1;
   //第三通道接正电源测试
   err = writeSingleRegister(CH2_CFG_ADDRESS, CH2_CFG_MUX2_DC_DIAGNOSTIC);
   if(err != 0)return -1;
   //第四通道接正电源测试
   err = writeSingleRegister(CH3_CFG_ADDRESS, CH2_CFG_MUX2_DC_DIAGNOSTIC);
   if(err != 0)return -1;
   //第五通道接负电源测试
//    err = writeSingleRegister(CH4_CFG_ADDRESS, CH3_CFG_MUX3_AC_DIAGNOSTIC);
//    if(err != 0)return -1;
   //第六通道接负电源测试
   err = writeSingleRegister(CH5_CFG_ADDRESS, CH3_CFG_MUX3_AC_DIAGNOSTIC);
   if(err != 0)return -1;
   //第七通道接负电源测试
   err = writeSingleRegister(CH6_CFG_ADDRESS, CH3_CFG_MUX3_AC_DIAGNOSTIC);
   if(err != 0)return -1;
   //第八通道接负电源测试
   err = writeSingleRegister(CH7_CFG_ADDRESS, CH3_CFG_MUX3_AC_DIAGNOSTIC);
   if(err != 0)return -1;