DAC80502: issue in SPI clock pin of DAC80502EVM

SMPL

Part Number: DAC80502

I am using DAC80502EVM module and interfaced it with LAUNCHXL F28379D using SPIA. Whenever I try to send 24bit data to change the DAC module output it does not change automatically. Instead I have observed that if I connect an unloaded (not connected to DSO) voltage probe between TP1 (CLK input of the module) & TP2 (ground), then only I can change the output of DAC by sending 24bit data using SPI. I realized this is may be due to some noise in the clock channel. I have used a 10nF capacitor to filter out noise, but it is of no use. The module can only work if a unloaded voltage probe is connected as mentioned above. Kindly help in this regard.

Thanks.

over 1 year ago

0 Erin Bowrie over 1 year ago

TI__Genius 10990 points

Hello,

There's a few things we can check. Firstly, are you able to validate the noise on the clock channel? Or does connecting an oscilloscope probe appear to clear it? Second, what is the state of JP2? This jumper needs to be populated to set the SPI mode.

Thanks,
Erin

0 SMPL over 1 year ago in reply to Erin Bowrie

Intellectual 561 points

Hello Erin,

Thanks for the reply. I have resolved the issue. The main problem was with the clock signal as it was not proper. I guess because of probing at clock input, the clock signal was getting compensated.

0 Katlynne Jones over 1 year ago in reply to SMPL

TI__Mastermind 42273 points

Hello,

Thanks for confirming you resolved your issue. Please let us know if you if you run into any more trouble.

Best,

Katlynne Jones

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DAC80502: issue in SPI clock pin of DAC80502EVM