TI中文支持网Other Parts Discussed in Thread:LMP91000
各位TI专家们好，我在用LMP91000，然后参考电压为3.3v, 零压为50%。然后用万用表测得WE得电位为3.4V, CE的电位为1.67， RE 电位为0。这是什么原因，不是在RE和WE之间设置了偏压吗？
#define TI_LMP91000_TIACN_REG_VALUE (0x1F) /* default r=14k*/
#define TI_LMP91000_REFCN_REG_VALUE (0x28) /* default */
#define TI_LMP91000_MODECN_REG_VALUE (0x03) /* default */
user6494387：
各位TI专家好，我在用LMP91000作为电化学测试，然后发现空载时，测WE与CE之间有一个电压值，大小为50%VREF，然后参比电极和工作电极之间电压为0.
但我设置的不是参比电极和对电极之间的偏压为一定的值吗？
为什么是这种情况，我这种情况是正确的吗？代码如下：
#define TI_LMP91000_TIACN_REG_VALUE (0x1F) /* default r=14k*/#define TI_LMP91000_REFCN_REG_VALUE (0x28) /* default */#define TI_LMP91000_MODECN_REG_VALUE (0x03) /* default */
uint8_t read_val[2]; uint8_t status = TI_LMP91000_NOT_READY;
//WDTCTL = WDTPW + WDTHOLD; // Stop watchdog timer
//TI_LMP91000_LED_PxOUT |= TI_LMP91000_LED_PIN; // Set LED ON//自己根据实际情况更改，串口输入输出 //TI_LMP91000_LED_PxDIR |= TI_LMP91000_LED_PIN; // Set pin direction is output
I2CSetup(LMP91000_I2C_Address); // Initialize I2C module
//TI_LMP91000_MENB_PxOUT &= ~TI_LMP91000_MENB_PIN; // Enable \MENB Pin，同上 //TI_LMP91000_MENB_PxDIR |= TI_LMP91000_MENB_PIN; // Set pin direction is output
while (status == TI_LMP91000_NOT_READY) status = LMP91000_I2CReadReg(TI_LMP91000_STATUS_REG); // Read device ready status
LMP91000_I2CWriteReg(TI_LMP91000_LOCK_REG, TI_LMP91000_WRITE_UNLOCK); // unlock the registers for write
LMP91000_I2CWriteReg(TI_LMP91000_TIACN_REG, TI_LMP91000_TIACN_REG_VALUE); // Modify TIA control register LMP91000_I2CWriteReg(TI_LMP91000_REFCN_REG, TI_LMP91000_REFCN_REG_VALUE); // Modify REF control register
read_val[0] = LMP91000_I2CReadReg(TI_LMP91000_TIACN_REG); // Read to confirm register is modified read_val[1] = LMP91000_I2CReadReg(TI_LMP91000_REFCN_REG); // Read to confirm register is modified
if ((read_val[0] != TI_LMP91000_TIACN_REG_VALUE) || (read_val[1] != TI_LMP91000_REFCN_REG_VALUE)) // test values took effect while (1); // otherwise error
// lock the registers LMP91000_I2CWriteReg(TI_LMP91000_MODECN_REG, TI_LMP91000_MODECN_REG_VALUE); // 3-lead amperometric cell LMP91000_I2CWriteReg(TI_LMP91000_LOCK_REG, TI_LMP91000_WRITE_LOCK);
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Amy Luo：
您好，
可变偏置电路在RE电极和WE电极之间提供偏置气体传感器所需的偏置电压量，因此为了验证控制放大器是否正常工作，您需要在连接传感器的情况下测量WE和RE之间的电压
