We have a Problem with a KV5XP Controller:
A USB to UART Bridge is connect at the Controller, the Bridge is supplied over the USB-Power.
The problem occur when the USB is connect and the Power of the controller is down. The TXD of the Bridge give a high level signal (3,3V) to a controller-pin. This voltage level make a indirect power supply on the 3,3V rail of the controller.
How i can solve this problem?