This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

TPS23881EVM-008: Not Responding Over I2C

Part Number: TPS23881EVM-008
Other Parts Discussed in Thread: TPS23881



The issue that I am facing is that TPS23881EVM-008 is not responding on I2C, a Few months back It was working fine but is not even appearing in the simple I2C scan.

I am providing it the required 54 Volts by adapter I checked and it is getting it on its pins, I also provided the 3.3V and GND from stm32 and checked on its pins with DMM, and it is showing 3.28V.

I am pulling the reset pin down for 10ms and then pulling it up. and then try to communicate with it over i2c. but no response.


My main code was working fine a few months ago but now after this no response over i2c 

I wrote this small snippet to check it, I also tested it with other i2c sensors which show up in the scan but TPS23881 is not showing up.

  HAL_StatusTypeDef status;
  for (uint8_t address = 1; address <= 127; address++) {
      // Try to read one byte from the current device address
      status = HAL_I2C_IsDeviceReady(&hi2c3, address << 1, 1, HAL_MAX_DELAY);
      if (status == HAL_OK) {
          // Device found at this address
    	  SerialDebug( strcpy((char*) debugBuff, "---------Device Found\r\n") );
      }
  }



So please guide what is the issue is there something else I can try?

  • Hi Hamas,

    Can you confirm the only connections to the device are the I2C SDA, SCL, GND and RESET? No OSS connection?

    I would also ensure the TPS23881 follows the correct power on sequence. The UVLO of the VPWR must be cleared prior to VDD being asserted. If VDD is asserted at the same time or prior to VPWR clearing the UVLO flag it could cause some device issues.

    It looks like pins A4-A1 are all grounded, therefore I2C address should be 0x20.

    Regards,

    Brandon

  • Yes only connections are I2C SDA, SCL, GND, and RESET

    "The UVLO of the VPWR must be cleared before VDD is asserted. If VDD is asserted at the same time or before VPWR clears the UVLO flag it could cause some device issues."

    I checked it in the datasheet but didn't understand it. If I am getting it right then it means first providing VWPR (52V)
    then after some delay provide VDD (3.3V).

  • Hamas,

    TPS23881 has a power on sequence that needs to be met. 

    RESET pin must be held low before VPWR reaches its UVLO. Can you capture a waveform including VPWR, VDD and RESET pin? Thanks.