Hi All,
I control LED driver (PCA9955B) using i.MX RT1064. After I set each register and LED1 pin is output. However waveform from LED1 pin is negative voltage(-0.24V). The power supply of PCA9955B is 3.3V. What are the possible causes of this phenomenon? It is unknown whether software or hardware.
<PCA9955B data sheet>
https://www.nxp.com/docs/en/data-sheet/PCA9955B.pdf
Hi Jose,
Thank you for your reply.
The cause was hardware. I'm sorry to have caused you trouble.
Best regards,
Hi,
When you mentioned ‘waveform from LED1 pin is negative voltage(-0.24V)’, is this a negative spike or the voltage maintains at this level all the time?
I could use waveforms and schematics for a review.
Thanks
Jose