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AFE4300: VREF Always 0V, RDY Pin always high

Part Number: AFE4300

hi

first, I apologize to my bad English.

I have a problem while developing AFE4300.

The Vref pin is always high even though I setting registers well and providing 3.3V 1MHZ clock.

and RDY pin is high since the power is turned on.

There is no problem reading and writing registers. It read the same value as the one I wrote.

Here is the value that I write to AFE4300.

AFE4300_SPI_Write(AFE4300_ADC_CONTROL1, 0x4140);
AFE4300_SPI_Write(AFE4300_MISC1, 0x0000);
AFE4300_SPI_Write(AFE4300_MISC2, 0xFFFF);
AFE4300_SPI_Write(AFE4300_WEIGHT_SCALE_CONTROL, 0x0000);
AFE4300_SPI_Write(AFE4300_BCM_DAC, 0x0040);
AFE4300_SPI_Write(AFE4300_DEVICE_CONTROL2, 0x0000);
AFE4300_SPI_Write(AFE4300_MISC3, 0x00C0);

AFE4300_SPI_Write(AFE4300_DEVICE_CONTROL1, 0x6006);
AFE4300_SPI_Write(AFE4300_VSENSE_MUX, 0x0408);
AFE4300_SPI_Write(AFE4300_ISW_MUX, 0x0408);
AFE4300_SPI_Write(AFE4300_IQ_MODE, 0x0000);
AFE4300_SPI_Write(AFE4300_ADC_CONTROL2, 0x0063);

Thanks for your help.

  • Hi,

    Can you try same register settings without reading any back. This is important because, in AFE4300 if you read a register the register content gets corrupted and you have to write back the proper value again.
    Also, since you are in BCM mode, can you probe the DAC_OUT pin and confirm that you get a sine wave of the set BCM frequency. If not, that means AFE is not getting a clock.

    Regards,
    Prabin
  • Because the value is read well, I excluded the reading part the next time when i run the code. 

    Therefore, this is not a problem caused by reading the register.

    I was able to get this waveform at DAC_OUT.

    And this is the 1Mhz clk that I supply to AFE4300.

    But Vref still low and RDY pin is always high.

  • I didn't read register since it reads register well. And i can get 60Hz sine wave at DAC_OUT. But Vref pin is still low and VLDO pin is still low too.
  • Hi,

    Looking at the images, it is clear that AFE is not getting the CLK.
    Can you share the schematic of your board and check the connection of CLK pin to the board.
    The sine wave at the DAC_OUT is ~60Hz, so it could be AC mains frequency.
    Also MISC_REISTER3 should be written 0x0030 not 0x00C0.

    Regards,
    Prabin