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AD9148 Configuration

Thread Summary

The user is experiencing issues with the AD9148 DAC, specifically not reaching the full-scale current of 20 mA on the 4 outputs and an unexpected 2 mA current on IoutN when generating 20 mA on IoutP. The user is using a custom setup similar to the schematic in Fig. 78 of the datasheet, in single-port mode with unsigned binary format. The support engineer confirmed the expected behavior using the AD9148 Evaluation Board and requested the user's full schematic for further troubleshooting.
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Product Number: AD9148

Hello,
I am having a lot of trouble using the AD9148.
I set the AD9148 with a full scale of 20 mA
I try to generate a current between 0 and 20 mA on the 4 outputs of the AD9148, but I never manage to reach the value of the full scale, the value reached is 18 mA, the DAC is used with a circuit similar to the one described in page 62 of the datassent figure 78.
the other problem I encounter is when I try to generate a current of 20 mA on IoutP, I have only 16 mA on IoutP and 2mA on IoutN, whereas I am supposed to obtain a current close to 0 mA on the IoutN output.
What is the possible cause of this dysfunction ?
the other point which poses problem is the configuration of the registers, indeed when I try to add an offset current by setting the registers 2C, 2D, 2E and 2F, there is no change whatever the value written in these registers. I meet the same problem with the registers 0x50 and 0x51.

I use the DAC in the following configuration:
Afull scale = 20 mA
Data format : unsigned binary format, single port .
Is there a particular configuration for setting the registers?

Thank you in advance for your help, I do not understand the cause of these problems


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