In a CAN bus network, what is the purpose of termination resistors at the ends of the network?

• A. To increase signal speed.
• B. To provide power to the bus.
• C. To prevent signal reflections and ensure proper high-speed communication.
• D. To encrypt data.

Answer: (C)

Impedance matching of the CAN bus through termination resistors at the ends. In a CAN network, the two-wire line has a characteristic impedance. Placing a resistor across the pair at each end matches that impedance, so energy that reaches an end is absorbed rather than reflected back along the cable. Reflections can distort the differential signal, cause timing issues, and lead to bit errors, especially on longer runs or with multiple devices. Proper termination keeps the voltage transitions clean and maintains reliable high-speed communication by preventing those reflections. The resistors don’t supply power or encrypt data, and they mainly serve to preserve signal integrity for the bus.