Hi,
I am using the PM8805. I need Class 3 and 4 and so I used datasheet's table 7 (classification table) which says, that one resistor 36R5 is needed on CLS1 pin and a open connection is needed on CLS2 pin. There should be the result 0 on T0 output for PSE provided class 4, and 1 on the T0 output for a class 3 provided by PSE.
When I got the board I connectefound out that the classification always gives me 1 on T0 and 0 on T1, I looked at the event "fingers" sent from PSe and there were 4 fingers each time.
After troubleshooting and studying TI's PD controller datasheets, we realized that there has to be an additional resistor on CLS2 output. This has to be around 36R5 also. If I will put this value on CLS2 pin the T0 and T1 outputs give the signals one would wait for, and the fingers are also reduced to a number of 3 (with this PSE).
Can you give me a hint why this is the case and why it is not written to the datasheet of the PM8805 (neither version of 2017 nor version of 2019), if it is a known fact?
Also I can reda in teh datasheet that the CLSx resistors should be 0805 size. Why can't they be smaller like 0402?
Thank you for your kind efforts!
Best regards
Wolfgang
