TLIN1029A-Q1: I am looking for RS 485 (THVD2410DR) to LIN BUS Converter (TLIN1029A-Q1) without changing in the current schematic through external daughter Board.

Hi Chandan,

I don't think you can connect the TTL side of an RS485 device to a LIN transceiver's TTL side. The problem is there is a looparound where the transceiver will see it's own output and send it back through the TTL signal. 

You probably need to set up a MCU to sit on the external board and act as a bridge to take in the RS485 TTL then have the MCU send through LIN and vice versa. Otherwise I believe the bus will end up getting stuck since the LIN transceiver would see it's own output and drive RX. 

-Bobby

Do you need a MCU to be a bridge between UART and LIN? Then MSPM0L1105/6 may be a good option.

MSPM0L1106 data sheet, product information and support | TI.com