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Use OP AMP(AD797) as DAC(AD5445) output buffer

Dear all,

Please help me:

I want to use an OP AMP(AD797) as the buffer of DAC(AD5445).

We need Positive output voltage (0~3.3V) , but the reference design use one more OP AMP and LDO (ADR03).

I just want use just one OP AMP as I-to-V converter.

I found this configuration:

My question:

(1) RL is need?

(2) Pin RFB connect to ?

Is the following scheme OK?

Thank you in advance!

Best Wishes,

William

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  • William,

    I don't beleave either configuration is going to work for you, but have not benched either to see. I think at best you're going to see only 1/2 the range.

    As per the datasheet, the standard way to get to the possitive ourput is as shown. I don't see a way around the need to generating a negative reference into the DAC, since the amp is going to invert the signal.

    https://ez.analog.com/cfs-file/__key/communityserver-discussions-components-files/427/320e8aecea7c39045f981ddffdb9a6be.html

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  • William,

    I don't beleave either configuration is going to work for you, but have not benched either to see. I think at best you're going to see only 1/2 the range.

    As per the datasheet, the standard way to get to the possitive ourput is as shown. I don't see a way around the need to generating a negative reference into the DAC, since the amp is going to invert the signal.

    https://ez.analog.com/cfs-file/__key/communityserver-discussions-components-files/427/320e8aecea7c39045f981ddffdb9a6be.html

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