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DAC81401: Help review shchmatic

Part Number: DAC81401
Other Parts Discussed in Thread: LM2904V, TLV9101, TLV172

Tool/software:

Hi team,

Could you help review DAC81401 schematic as attached. thanks 

DAC81401.pdf

  • Hi Jimmy,

    Schematic looks okay to me. Few questions : 
    1. Are you using internal reference ?
    2. What is the USB of LM2904V  opamp that you have used in the DAC OUT and VSENSEP path ?

    Thanks,
    Sanjay

  • Hi team,

     

    1. Are you using internal reference ?

    Yes, we are using internal reference.

     

    1. What is the USB of LM2904V  opamp that you have used in the DAC OUT and VSENSEP path ?

    LM2904V is used as a buffer between DAC81401 and external devices.

  • Hi Jimmy,

    I wanted to know UGB - unity gain bandwidth (not USB) of the LM2904V (U24A, U24B). This is ensure the loop stability for DAC output.

    Thanks,
    Sanjay

  • Hi Sanjay,

    The frequency response of LM2904V is as shown below. The signal we provide to the load is 0~10V, and the load operates in

  • Hi Jimmy,

    DAC81401 output will be unstable with LM2904V as buffer in VSENSEP path. And also output signal BW will degrade with LM2904V as buffer in output path.

    Please choose :
    1. OUTPUT buffer : BW more than 1MHz
    2. VSENSEP buffer : BW more than 3x BW of OUTPUT buffer

    Thanks,
    Sanjay

  • Hi team,

    Do you have a suggestion for OUTPUT buffer and  VSENSEP buffer ? thanks 

  • Hi Jimmy,

    You can use the parts mentioned below:

    1. OUTPUT buffer :TLV9101
    2. VSENSEP buffer :TLV172

    Thanks,
    Sanjay