Question:
Can the MAX3140 support data rates up to 10Mbps?
Answer:
No. The MAX3140 should not be used for rates above the standard 230kBaud. The confusion over the 10Mbps RS485 is due to the fact that the MAX3089 RS-485 transceiver is inside the MAX3140 product. While the MAX3089 can operate at 10Mbps, the UART combination cannot.
Recommendations for higher throughput include the MAX3107 and MAX3108. These UARTs do not include the RS485 transceiver, but they have a much faster SPI interface (26MHz clock) and the baud rate generator is far more flexible allowing up to 24Mbps data rates with external transceivers.