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I have some problem about MMA8652's low power

Question asked by JunLin Wu on Aug 18, 2016
Latest reply on Aug 19, 2016 by JunLin Wu


    I have some problem about MMA8652 . I set the ODR=1.56(CTRL_REG1=0x38) , and work in low power mode(CTRL_REG2=0x1b) . It's current should be 6.5 uA.


   But I read the current is 170 uA with digital ammeter . Why?

And my Schematic like that


my code is


IIC_write(CTRL_REG1,0x38);              //ODR = 1.56Hz, standby

IIC_write(XYZ_DATA_CFG_REG,0x02);       //+/-8g

IIC_write(CTRL_REG2,0x1b);              //Low Power


  IIC_write(PULSE_CFG_REG, 0x15);         //Enable X, Y and Z Single Pulse

  IIC_write(PULSE_THSX_REG, 0x78);        //Set X Threshold to 7.56g

  IIC_write(PULSE_THSY_REG, 0x78);        //Set Y Threshold to 7.56g

  IIC_write(PULSE_THSZ_REG, 0x78);        //Set Z Threshold to 7.56g


  IIC_write(PULSE_TMLT_REG, 0x28);        //Set Time Limit for Tap Detection to 25 ms

  IIC_write(PULSE_LTCY_REG, 0x28);        //Set Latency Time to 50 ms


  IIC_write(CTRL_REG4, 0x08);             //Pulse detection interrupt enabled

  IIC_write(CTRL_REG5, 0x08);             //Route INT1 to system interrupt


  data = IIC_read(CTRL_REG1);   //Active Mode

  data |= 0x01;

  IIC_write(CTRL_REG1, data);


Thank you ! every body!