Hello,
I am currently using the TPD4S014 in multiple designs and on odd behavior has been noticed on all 3 designs. When the VBUS is removed (USB cable is detached) the ACK signal is de-asserted (as expected) after it crosses below UVLO-. Strangely, after a long period of time (roughly 600mS) it is re-asserted for about 750mS before de-asserting again and staying that way. The timing is consistent on each design, but is marginally different between the designs. I've arrached a scope capture of VBUS (green) and ACK (yellow). All devices are powered via a single Li-Ion battery. The ACK signal is connected directly to an MSP430 input pin and pulled up to VCC (3.3v) with a 10K resistor.
Is this typical behavior or to be expected? If not any ideas on what could be the source of this bahavior?
Thanks
-Chris