Paradigm Shift: EV Full Ecosystem Opportunities - The CAN SIC Transceiver Is Ready to Go

Introduction

 The electric vehicle (EV) trend is driven by three main factors: increasing environmental awareness, advancements in battery technology, and growing market demand. According to an analysis by the International Energy Agency (IEA), approximately 14 million EVs were purchased globally in 2023, with an estimated 40 million EVs already on the road. With supportive government policies, global EV ownership is projected to increase 12-fold by 2035. As the demand for smarter EVs rises, the internal network architecture will evolve, steering towards Software-Defined Vehicles (SDVs) in the next generation. This transformation will require higher data transmission bandwidth to enhance user experience and support upgrades in autonomous driving technologies.

CAN SIC Transceiver

Mainstream System-on-Chip (SoC) solution providers anticipate that SDV architectures could see mass adoption as early as 2026–2027. This architecture is expected to reduce the number of in-car ECUs (Electronic Control Units) by approximately 30%, enabling automakers to develop software independently. This allows users to download updates directly, eliminating the need for time and cost of intensive hardware replacements. In the SDV architecture, the introduction of regional controllers demands larger data bandwidth to handle increased message traffic. The upgrade of CAN (Controller Area Network) bus transceivers and the integration of automotive Ethernet will address these demands. For example, CAN FD (Flexible Data Rate) will evolve into CAN SIC (Signal Improvement Capability), increasing speed from 5 Mbps to 8 Mbps. Meanwhile, backend connections from regional controllers to the main control computer will adopt automotive Ethernet technology, achieving speeds of 10 Mbps to 1 Gbps or higher. 

With the adoption of next-generation Software-Defined Vehicle (SDV) architectures, the network connections between controllers are becoming increasingly complex. This complexity can degrade signal quality on communication buses, causing signal reflections that render the widely used CAN FD physical layer technology insufficient for upgraded applications. The AZKN9325P is a CAN SIC transceiver equipped with built-in ring suppression technology, compliant with CiA 601-4 and ISO 11898-2:2024 standards. Utilizing proprietary patented technology, it ensures compliance with automakers' electromagnetic compatibility (EMC) requirements even under high-speed transmissions. There are two primary application scenarios where CAN SIC is recommended: 1. For enhancing network topology into star or hybrid configurations (e.g., daisy-chain with dual-star topology). The ring suppression technology effectively addresses severe signal reflections caused by these complex topologies. 2. For achieving higher transmission bandwidth in existing hardware architectures, such as increasing communication packet speed from 2Mbps to 5Mbps or higher. 

The principle of the AZKN9325P lies in its ability to suppress signal reflections caused by complex network topologies. This is achieved through its internal circuitry, which optimally controls bus impedance matching when the transmitter transitions from a low-impedance Dominant state to a high-impedance Recessive state. Using TX-based signal optimization technology, the chip controls the time from the TXD signal's rising edge to the end of the signal improvement phase within a maximum of 530ns. The TX-based CAN SIC design aligns with automakers' expectations for energy-saving network architectures. It supports an STB (standby) mode, allowing the ECU to define standby functionality by shutting down the transceiver's internal high-speed receiver to achieve power-saving. Regarding its electrical characteristics, the communication lines can handle a maximum voltage of ±42V and directly connect to 1.8V SoCs or FPGAs. For ESD performance, the chip exceeds internal standards set by German automakers and complies with ISO 7637, HBM, and CDM requirements. Additionally, the external communication bus supports an IEC 62228-3 standard defined electrostatic discharge level of up to ±8kV. The AZKN9325P also allows Tier 1 suppliers to evaluate the feasibility of eliminating external protective components in controller circuit designs based on specific testing requirements from different automakers.

Rigorous Testing and Evaluation

To verify the automotive readiness of CAN SIC transceivers, evaluations include ISO16845-2 compliance testing and IEC 62228-3:2019 electromagnetic compatibility (EMC) testing. Compliance tests define procedures for ensuring components meet relevant standards, incorporating static and dynamic tests to guarantee product quality. EMC testing assesses the transceiver’s performance under different communication conditions, requiring top-level speed and robustness to ensure compatibility across various controllers and transmission speeds. For CAN SIC evaluation, additional testing for 5 Mbps transmission and timing requirements was conducted. Using Single Device Tests (SDT) with precision-controlled components (1% tolerance for resistors/capacitors and 5% for inductors), ringing networks were simulated to observe results with CAN FD transceivers. Figure 1 compares the ringing suppression effects of CAN FD and CAN SIC under 1Mbps and 8Mbps transmission environments. The simulation involves inputting an original TXD signal and applying a ringing network defined by the CiA 601-4 standard. When the bus transitions from a Dominant State to a Recessive State, the AZKN9325P, equipped with ringing suppression technology, shows no erroneous transition behavior in the RXD signal. In contrast, the AZKN9125P, which lacks this technology, exhibits issues. This demonstrates that the AZKN9325P ensures communication reliability and stability.

Figure 1: Comparison of Ring Suppression Performance Between CAN FD and CAN SIC Transceivers in 1Mbps and 8Mbps Transmission Environments  

Conclusion

Our mission is to continuously develop next-generation CAN bus transceiver technologies, enhancing transmission speeds and supporting more energy-efficient modes to drive electric vehicles toward smarter applications. The AZKN9325P CAN SIC is expected to see widespread adoption in Software-Defined Vehicle (SDV) architectures and gradually expand to industrial automation and on-site hardware upgrades. Facing an intelligent future, we are committed to achieving energy savings for specific controllers from a network perspective, steadily delivering products that meet automaker requirements, and continuously driving innovation in the automotive industry.