I have a homemade PCB with a TH3122 and atmega328p on it. I've function tested everything on the uC side to make sure all pins are correct, as well as scoped the KBUS going into the TH3122. I get 5V from 12V in on the TH3122, I have EN tied to 12V and VTR tied to 5V. When there is activity on the KBUS RxD remains 0V, additionally regardless of KBUS activity SEN/STA remains stuck at 5V. SEN/STA is tied to an input on my uC.
Anyone seen this? Is my TH3122 chip bad?