• Question about the AD7799 SPI register writing.

    Hello everyone, 

    I am debugging the AD7799 ADC. I check the generic code from wiki.analog.com. But I found that there is a byte "0x03" in the beginning of the sequence of bytes. Why it happens? I didn't find anything about it in the AD7799 manual. Thanks…

  • RE: I would like to receive the RoHS certificate of AD7799


    Apologies. I know this is long overdue. But just in case you still need some help or if someone have similar concern.

    The 'Z' suffix in the ordering guide means that this model is RoHS Compliant. See the general compliance document, here.

  • AD7799 Noise Sources

    When using the AD7799 in my own implementation, I am seeing a noise (at Gain=6, Rate=16.7) of around 2-4uV. When I use the Eval-AD7799 board, I get a noise of about 0.1-0.3uV. I have tried multiple input filter configurations (the Eval board has none)…

  • Power supply noise problem for AD7799

    I have a noise problem when using the AD7799 when the power supply (5V) is shared with a Raspberry Pi. When the Raspberry Pi is shutdown, the ADC noise levels are within spec when powered by various switching power supplies, including being powered by…

  • Determining best Calibration Values for AD7799

    In a typical weigh scale application with VCC = 5v, the maximum output from the load cell is typically 10mV. At maximum gain=128 with Vref = 2.5v, the maximum input value would be 3.78 volts. The system calibration in my application is performed by the…

  • Driving AD7799 with 3.3v logic and 5v supply


    I am planning to switch to using a 3.3v MCU for communicating with the AD7799 which will still be running at Vcc=5 volts. If I place a resistor divider on the DO line (to protect the MCU), do you see any problem with using 3.3v logic to the DI & SCK…

  • Need a help with AD7799

    Dear EngineerZone community

    Please support.

    The ADC was working fine in the beginning, but after a couple of weeks it started behaving like this.

    When I get the values from the AD7799 they are equal 0x000000 when the load cell is unloaded AND


  • RE: AD7799 Linux Driver

    I have confirmed having a second pin on the microprocessor connected to DOUT/~DRDY allows use of the interrupt driven approach. 

    It is odd, however, that to have this work I need to set the additional pin edge to "falling" directly from user space to enable…

  • Anti-alias filter causing excess noise in AD7799


    If I use the anti-alias filter circuit below, I get noise levels around 15uV, which is fine for my application. However, I need to use an anti-alias filter with Fc~=10Hz. So, changing C6=10uF, and C5=C7=1uF, I obtain the filtering I want from a low…

  • RE: AD7799的差分输入问题

    This question has been closed by the EZ team and is assumed answered.