Help with the MC33664 application

[Snow8124]

I'm using the MC33664 with the MC33775. The MC33664 is receiving power normally, and the EN pin is set to high. The INTB pin is pulled low, but the measured output voltages on the RDTX+ and RDTX- pins are both 0. Could someone please help me figure out why this is happening

[Snow8124]

Hello,
Thank you very much for your reply last time.Following your suggestion, we re-examined the circuit and found that the RDTX+ and RDTX- pins on the MC33664’s output stage are at 2.5V, but the voltage measured on the secondary side of the transformer is 0V. We would like to confirm with you whether this behavior is normal.We look forward to your response.

[RafaR · Accepted solution]

Hello Snow8124

Good Day!

So does INTB stay low all the time?

It sounds like you're having a problem with the wake-up or initialization sequence. I recommend you review chapter 12 of the datasheet and this application note:

I hope this information has helped you, please let me know if you need help with anything else.

Have a great day and best of luck.