The Isolated RS-232 port is implemented using the ADM3252E Signal and Power isolated RS-232 transceiver. The ADM3252E connects to UART3 of the ADSP-BF548 and is capable of functioning at data rates of up to 460kbit/s. Figure 1 below shows a circuit diagram of the implementation of the ADM3252E on the ezLINX hardware.
The VCC of the ADM3252E is powered with 3.3V and will generate an isolated 3.3V on VISO using ADI’s isoPower technology.
A three pin screw terminal connector, J6 is used for easy access to the TOUT1(pin 2), RIN1(pin 3) and RS232_ISO_GND(Pin 1) connections. The jumper JP2 when fitted will connect the transmitter output(TOUT1) to the receiver input(RIN1), implementing a loopback feature.