ROHM’s New TVS Diodes: Supporting High-Speed CAN FD In-Vehicle Communication Systems for Autonomous Driving

　　ROHM has developed bidirectional TVS (ESD protection) diodes compatible with CAN FD (CAN with Flexible Data rate) high-speed in-vehicle communication. Such protocols are seeing an increased demand in line with the ongoing advancement in autonomous driving and advanced driver assistance systems (ADAS). CAN FD is a crucial communication technology for safe, real-time data transmission between ECUs (Electronic Control Units) in vehicles. The new products achieve high-quality in-vehicle transmission by protecting electronic devices such as ECUs from surges and electrostatic discharge (ESD) while maintaining signal integrity in high-speed communication systems such as CAN FD.

　　The rapid evolution of autonomous driving technology and ADAS is boosting the demand for faster, more reliable automotive communication. Autonomous driving in particular requires quick and accurate processing of vast amounts of data from sensors such as cameras, LiDAR and radar - leading to the adoption of CAN FD that enables faster, higher capacity data transfer compared to traditional CAN used in automotive communication.

　　At the same time, to achieve high-speed in-vehicle communication, it is necessary to ensure stable transmission even under harsh environments. This has led to a growing demand for protection components that offer low terminal capacitance along with superior surge current rating and clamping voltage performance. As a result, the market for TVS diodes for automotive communication is expected to continue to grow in the future.

　　To meet market needs, ROHM developed the ESDCANxx series that combines low terminal capacitance with excellent surge tolerance. Two package types are available: SOT-23 (2.9mm × 2.4mm) and DFN1010 (1.0mm × 1.0mm), both supporting standoff voltages (VRWM) of 24V and 27V. The SOT-23 package includes four models: 24V ESDCAN24HPY / ESDCAN24HXY and 27V ESDCAN27HPY / ESDCAN27HXY. Similarly, the DFN1010 package is also offered in four models: 24V ESDCAN24YPA / ESDCAN24YXA and 27V ESDCAN27YPA / ESDCAN27YXA, totaling 8 products in the lineup.

　　The new products feature an optimized element structure that reduces terminal capacitance to a maximum of 3.5pF, preventing signal degradation during high-speed communication. High surge tolerance is also achieved, significantly improving the protection of electronic devices in automotive environments. For example, the 27V products of the DFN1010 package delivers approx. 3.2 times higher surge current rating and 16% lower clamping voltage compared to standard CAN FD-compatible products. This effectively safeguards expensive surge-sensitive electronic devices such as in-vehicle ECUs, ensuring high reliability even under harsh automotive environments. Going forward, ROHM will continue to develop products that support even faster in-vehicle communication in autonomous driving and communication environments - contributing to realizing a safer, more advanced mobility society.

　　Application Examples

        • Autonomous driving and Advanced Driver Assistance Systems (ADAS)

　　• Automotive electric powertrain systems

　　• In-vehicle infotainment systems

　　Online Distributor Information

        Sales Launch Date: December 2024

　　Pricing: $0.9/unit (excluding tax)

　　Target Products

　　SOT23 Package: ESDCAN24HPY, ESDCAN24HXY, ESDCAN27HPY, ESDCAN27HXY

　　DFN1010 Package: ESDCAN24YPA, ESDCAN24YXA, ESDCAN27YPA, ESDCAN27YXA

　　Terminology

         CAN FD (CAN with Flexible Data Rate)

　　An extension of the CAN (Controller Area Network) standard, CAN FD offers faster data transfer speeds compared to conventional CAN, enabling the exchange of large volumes of data. Real-time communication between multiple in-vehicle electronic units (ECUs) is essential in systems like autonomous driving and ADAS.

　　TVS Diode (Transient Voltage Suppression Diode)

　　A semiconductor device designed to protect circuits from overvoltage, surges, and electrostatic discharge (ESD). TVS diodes absorb sudden voltage and current spikes (surges) to prevent circuit damage and malfunction. In automotive environments, safeguarding against severe electrical fluctuations is crucial.

　　Terminal Capacitance

　　Unwanted capacitance components that arise in electronic parts. When terminal capacitance is high, signal degradation occurs during high-speed transmission, making it important to reduce terminal capacitance for in-vehicle communication

　　Surge Current Rating

　　The maximum surge current a TVS diode can withstand. The higher the surge current rating, the stronger the protection against severe electrical fluctuations in automotive environments.

　　Clamping Voltage

　　The voltage maintained in the circuit when the TVS diode suppresses overvoltage caused by surges or other transient events. A lower clamping voltage provides more effective protection for circuits and devices, increasing the reliability of automotive equipment.