A high-Speed CAN Bus Transmitter with Low Electromagnetic Emission

CAN (Controller Area Network) bus transceivers have high requirements for security and performance, which are mainly used in automotive networks, machine automation and other fields,. This paper designs and implements a high-speed CAN bus transmitter with low electromagnetic emission (EME). The slew rate of the output signal is reduced by successively controlling the switching of the transistor at the output end of the transmitter, and a negative feedback structure that can balance the current capability of the output power transistor is used to improve signal symmetry. The chip is designed based on 60V 0.18$\mu$ m BCD process. The test results show that at the transmission rate of 5Mbit/s, the output of the transmitter complies with the explicit and implicit requirements of the CAN bus level, the output common mode signal has good voltage symmetry, and the average value of the common mode FFT is 66.26dB, which can be applied to high in highly reliable CAN transceivers.