DAC161S997: Circuit diagram reference to used

Rohit6230

Intellectual 725 points

Part Number: DAC161S997
Other Parts Discussed in Thread: TIDA-00648, ,

Dear ,

We are using loop power 4-20mA transmitter. we are referring below 2 circuit reference,

TIDA-00648 reference design | TI.com

DAC161S997EVM User's Guide (Rev. A) (ti.com)

In both design we observed some component difference. Could you recommended me which design we refered to complete to test circuit?

As per our observation in TIDA-00648 diagram 1µf, 100V C10 capacitor has passing some leakage current in our devices after certain period of time and DAC161 EVM used tanta capacitor in same placed. which type of capacitor we prefer.

Please let me know which one we will used.

over 1 year ago

0 Lucas Burnette over 1 year ago

TI__Expert 4160 points

Hi,

Thanks for posting on our forums!

Reference Design vs EVM:

The DAC161S997EVM provides an easy way for the DAC161S997 to be evaluated and tested, with an easily configurable circuit.

The TIDA-00648 reference design shows a specific circuit using the DAC161S997 as a 4-20 mA loop transmitter.

If you are concerned mostly with performance and less with configurability, I recommend the TIDA-00648 reference design as your main resource.

1 uF Capacitor CERM vs TANT:

For the 1 uF capacitor, using a TANT capacitor will give you more reliability over a longer time range for capacitance.
However if you are concerned about leakage with the CERM capacitor, the TANT capacitor would typically have more leakage.
To lessen the leakage current, I would recommend looking at higher voltage rated CERM capacitors, like 160 V or 250 V.

Let me know if you have any other questions,

Thanks,
Lucas

0 Rohit6230 over 1 year ago

Intellectual 725 points

Thanks Lucas,

Value of tanta capacitor 1µF/100v or 1µF/50v also ok, because loop voltage up to 36Volt.

0 Lucas Burnette over 1 year ago in reply to Rohit6230

TI__Expert 4160 points

Hi,

A 50 V rating would be fine, but as I mentioned earlier, a higher voltage rating would lessen leakage current for a CERM capacitor.

Thanks,
Lucas

0 Rohit6230 over 1 year ago in reply to Lucas Burnette

Intellectual 725 points

Dear Lucas,

could you explain me the used of 1µf and 10nF capacitor in ciruit ? What happened if I removed this from circuit

0 Lucas Burnette over 1 year ago in reply to Rohit6230

TI__Expert 4160 points

Hi,

Those two capacitors are used as decoupling capacitors, which reduce the amount of high frequency noise present on the loop nodes.

You could potentially remove them if you don't need that fine of an accuracy.

Thanks,
Lucas

0 Rohit6230 over 1 year ago in reply to Lucas Burnette

Intellectual 725 points

Thanks Lucas, We will check condition with 250 Volt cap. Please find our schematic diagram and capacitor C32, C33.

I request to checked whole schematic and update me if there any changes?

+1 Lucas Burnette 12 months ago in reply to Rohit6230

TI__Expert 4160 points

Hi,

Capacitor C38 should be 220 nF (0.22 uF), not 22 nF.

Other than that, it looks good!

Thanks,
Lucas

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DAC161S997: Circuit diagram reference to used