Throughput Optimization in 5 Mbps CAN-FD: Bit Rate Switching (BRS) & Transceiver Delay Compensation

Abstract: Overcoming physical transmission line constraints, ringing, and transceiver propagation delays when switching from 500 kbps nominal arbitration to 5 Mbps data phases.

1. Bit Rate Switching (BRS) Dynamics CAN-FD achieves high bandwidth by maintaining a conservative 500 kbps nominal arbitration phase (where bus propagation across the entire vehicle harness must occur within one bit time) and switching to 2-5 Mbps for the control, data, and CRC fields.

2. Transceiver Delay Compensation (TDC) At 5 Mbps, a single bit lasts only 200 nanoseconds—often shorter than the round-trip propagation delay through the physical transceiver and wiring. Secondary Sample Points (SSP) and hardware TDC engines dynamically measure loop delays, shifting the receiver sample window to ensure zero bit errors during high-speed data transmission.