Bidirectional InfraRed PHY communication with a single IR LED

Some EU standards like EN1434-3 for heat meters require optical interface as per EN62056-21, where two separate IR LEDs are used (one for receive and one for transmit direction). TIDA-01212 shows an alternative approach, which uses a single IR LED to implement a bi-directional IrDA PHY link with 9.6 kbps in half-duplex mode. The design approach can the system reduce the cost of any smart (sub-)metering device by replacing the legacy optical IrDA PHY modules with two separate LEDs.