Various techniques are provided to facilitate a detection system to detect a presence of an externally coupled receiver device, such as a universal serial bus (USB) device. In one example, the system generates a reference current and passes the reference current via a conductor to a shared buffer circuit. The shared buffer circuit is adapted to selectively pass the reference current or a communication signal to the externally coupled receiver device. The system switches between a detect mode where the reference current is provided to the externally coupled receiver device and between a communicate mode where the reference current is blocked and the communication signal is provided to the externally coupled receiver device. The system monitors a voltage value of the conductor and the system monitors a time for the voltage value to reach a pre-determined threshold value in response to the reference current. The system detects a presence of the externally coupled receiver device based on the monitored time.