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PCA9955B: Short-circuit detection occurs repeatedly during the gradation operation

Question asked by Yannick Aeby on Mar 24, 2020
Latest reply on Apr 14, 2020 by G.w. Sun


I have problems with the short circuit detection of the PCA9955B led drive.

Short-circuit detection occurs automatically on all channels as soon as gradation continuous operation is started. They are false errors. The voltage V_O never exceeds the threshold voltage of 2.85V. The maximum measured voltage was 1.2V during gradation.

If I reset the errors, the short circuit error comes right back.

If I do not perform a gradation operation, the error register behaves correctly.


Any suggestion?

Thank you.