• State Resolved
  • Locked Locked
  • Replies 3 replies
  • Subscribers 46 subscribers
  • Views 680 views
  • Users 0 members are here
Support feedback
Options
Options
Related

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.

DAC80501: dac80501m

Minqi Zhao
Intellectual 1660 points
Part Number: DAC80501

Dear expert,

My customer is evaluating DAC80501M, but find output is nearly zero instead of midscale at no load condition. Besides, when writing a valid I2C code as below in p1, output is still nearly zero in p2. Please see schematic in p3 and share your suggestions, thanks.

  • 0
    TI__Mastermind 19086 points

    Hi,

    Thanks for writing to us.

    In your schematics, I can see REF is VDD . So I am assuming you are using external reference mode. Also VDD is 3.3V.

    After power up, You need to disable the internal reference and enable REF_DIV bit to 1, this will make sure that REF is divided by 2. Then you need to enable BUF_GAIN bit as well, make it 1, so BUF_GAIN will be 2. DAC output will be from 0 to Vref.

    Also as a debug, can you read STATUS register and let me know what you are reading? If you are reading FF, it will be due to not setting the REF_DIV bit.

    What's the I2C address? Pin A0 is high or low? I cant make out from your schematics.

    Regards,

    AK

  • 0 in reply to Akhilesh K
    TI__Intellectual 1660 points

    Hi，

    Thanks for your suggestion. Customer is using internal reference(L1 float), and checked the 2.5V reference voltage. 

    The I2C address is 10010000, A0 is connected by 10k resistor to ground. And the STATUS register is 1. Looking forward to your suggestions. Thanks.

  • 0 in reply to Minqi Zhao
    TI__Mastermind 19086 points

    Hi,

    If customer is using internal reference, set REF_DIV bit to 1 to enable divide by 2 and BUF_GAIN to 1 for gain of 2.

    Please follow this.

    After power up, You need to disable the internal reference and enable REF_DIV bit to 1, this will make sure that REF is divided by 2. Then you need to enable BUF_GAIN bit as well, make it 1, so BUF_GAIN will be 2. DAC output will be from 0 to Vref.

    If you are reading STATUS_REG as 1, which means there is not enough headroom between DAC supply and Reference which will be solved by enabling REF_DIV and BUF_GAIN bit.

    Hope this helps,

    Regards,

    AK