DRV425EVM: The output is 1.3X higher than the calculated output

Danilo A.

Part Number: DRV425EVM
Other Parts Discussed in Thread: DRV425

Hi Team,

Can you please help us regarding the customer's concern below.

I have been experimenting with the DRV425 and I am consistently getting an output value that is 1.31 times the value calculated per Equation 1. With B=0.5mT, my output value is 1.60 volts. Should be 1.218 based on Rshunt =49.9ohms. My supply voltage is 3.3V. I can't figure out why I have that discrepancy/ Do you have any ideas?

I use these devices in a linear array and they are spaced about 0.6" apart. Would that have any influence? I wouldn't think so, but I thought I would ask.

DVR425 Schematic diagram.pdf

Regards,

Danilo

over 3 years ago

0 Javier Contreras4 over 3 years ago

TI__Mastermind 27730 points

Danilo,

Is you schematic correct in that REFIN and REFOUT are floating. This could be the issue. Also are you measuring with respect to Vref. The output voltage will be with respect to Vref. Also is there any external magnetic fields around. You can verify this be turning off you magnetic field and Vout should be equal to Vref.

Let me know if this helps you find the issue.

0 Danilo A. over 3 years ago in reply to Javier Contreras4

TI__Mastermind 25495 points

Hi Javier,

The caused of the high output is the floating REFIN and REFOUT pins. Thank you very much for your inputs. The issue has been resolved.

Regards,

Danilo

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DRV425EVM: The output is 1.3X higher than the calculated output