1  Overview and Background

1.1  Key points of CNCA-C11-08:2026 new regulation

CNCA-C11-08:2026, the "Implementation Rules for Compulsory Product Certification – Indirect Vision Devices of Motor Vehicles" (trial), was issued by the Certification and Accreditation Administration of China on April 11, 2026, and became effective on July 1, 2026. It comprehensively updates the CCC certification requirements for motor vehicle indirect vision devices (including both traditional optical rearview mirrors and new CMS electronic mirror systems).

· From July 1, 2026: Certification bodies began accepting CCC certification applications under CNCA-C11-08:2026.

· From January 1, 2027: The new version becomes mandatory. Products that have not obtained CCC certification will no longer be permitted for sale, import, or use in business activities.

The most significant change in the new regulation is that CMS electronic mirror systems, as a new type of motor vehicle indirect vision device, are formally included in the scope of mandatory CCC certification. This means that EMC performance indicators such as ESD and transient disturbance are upgraded from recommended references to mandatory test items. Products must pass complete testing by designated laboratories before they can be certified and brought to market.

1.2  CMS (Camera Monitoring System) System Architecture

A typical CMS electronic mirror system consists of the following core components, forming a complete signal chain from image capture to display:

· External camera module: Installed on both sides of the vehicle (doors or fenders), integrating a CMOS image sensor, lens, GMSL serializer, and power management circuit. It is responsible for capturing real-time external images, operating in harsh exterior environments and facing the highest level of EMC threats.

· Cabin controller: Typically installed inside the cabin (dashboard or trunk area), equipped with a SoC main control chip. It receives and processes high-speed video data from both cameras, performs image stitching, latency compensation, brightness/contrast adjustment, and outputs video signals to both side displays.

· A-pillar display module: Installed on the inner side of the driver-side A-pillar or the door triangle area, using LCD or OLED panels. It receives video signals from the controller via MIPI DSI or LVDS interfaces, displays real-time external images, and replaces the field-of-view function of traditional optical rearview mirrors.

1.3  Associated standard system

The EMC certification testing for CMS electronic mirror systems involves a multi-level standard system. The CNCA-C11-08:2026 CCC certification implementation rules reference GB 15084-2022 Motor vehicles — Performance and installation requirements for indirect vision devices. GB 15084-2022 further references GB 34660-2017 Road vehicles — Electromagnetic compatibility requirements and test methods, which in turn references a series of basic EMC standards. Overall, this standard system includes:

2  Comparison of protection requirements before and after standard implementation

The implementation of CNCA-C11-08:2026 has elevated the EMC protection requirements for CMS electronic mirrors from "voluntary reference" to "mandatory access," fundamentally impacting product design. The table below systematically compares the key changes before and after implementation:

3  Electromagnetic interference threats faced by CMS systems

CMS electronic mirror systems operate in complex automotive electrical environments, facing multiple electromagnetic interference threats. A thorough understanding of the waveform characteristics and coupling paths of each threat is a prerequisite for developing effective protection solutions.

Electrostatic discharge (ESD) is the most direct and destructive electromagnetic threat faced by CMS systems. The external cameras are directly exposed to the outdoor environment; in dry climate conditions, human body model discharge or discharge from the human body to the vehicle body can directly affect the camera housing and connector.

Typical waveform characteristics of ESD events: extremely short rise time (0.7~1ns), peak current up to tens of amperes, spectrum ranging from a few MHz to several GHz. For high-speed signal lines in CMS systems (GMSL, LVDS, MIPI, etc.), ESD protection devices must have extremely low junction capacitance (Cj ≤ 0.5pF) to avoid signal integrity degradation. The ULC series ultra-low capacitance TVS devices from Shanghai Leiditech perfectly meet this requirement.

Transient disturbance threats in the vehicle environment are mainly manifested as various transient pulses defined in ISO 7637-2, of which the most destructive is the load dump pulse:

4  Shanghai Leiditech modular EMC protection strategy

（1）Camera module (high-risk exterior zone)

（2）Cockpit display / control module

（3）High-Speed Transmission Link (Camera – Controller)

· Core requirements: Ultra-low capacitance <0.5pF, high ESD protection, small package.

· Recommended solution: GMSL-dedicated automotive-grade ESD array (such as the Shanghai Leiditech ULC3304P10LVQ series), integrating 4-channel differential signal protection, DFN package, AEC-Q101 qualified, supporting 10Gbps+ data rates.

5 EMC protection solutions for each interface circuit

1. 12V power input protection

Use a P-channel MOSFET to meet the high-power reverse polarity protection requirements of automotive front-end equipment, with low heat generation, DFN5X6-8 package, and excellent thermal performance. The SM8S24CA or 5.0SMDJ24CA is used to meet ISO 7637-2 5A/5B testing, as well as ISO 10605:2008 (Level 4) ESD testing.

2.CAN interface ESD protection solution

雷卯EMC小哥推荐采用多路集成器件SMC24Q保护，电容<50PF，可以保证信号完整性的同时，可滤除杂讯、通过静电测试。

3.MIPI interface ESD protection solution

MIPI provides a transmission speed of 2.5Gbit/s. Leiditech recommends using the integrated device ULC3324P10LVQ for protection, with parasitic capacitance <0.5pF, ensuring signal integrity and meeting ISO 10605:2008 (Level 4) ESD testing.

4.LVDS interface ESD protection solution

LVDS provides a transmission speed of 655 Mbit/s. Shanghai Leiditech recommends the integrated device PUSB3FR4Q for protection. With a parasitic capacitance of <1pF, it ensures signal integrity and meets ISO 10605:2008 (Level 4) ESD testing requirements.试。

5. GMSL ESD protection solution

· Single-ended system (coaxial cable transmission): The single-ended system consists of a single coaxial cable that can carry 12V power, primarily used for automotive cameras. Shanghai Leiditech recommends the ULC1811CDNQ, with Cj=0.3pF (Typ.) low junction capacitance, ensuring signal integrity and meeting ISO 10605:2008 (Level 4) ESD testing requirements.

· Differential system (two differential pairs transmission): The differential system consists of two differential pairs, primarily used for in-vehicle high-definition central displays. Shanghai Leiditech recommends the integrated ULC3324P10LVQ, with Cj=0.45pF (Typ.) in a DFN2510 package, providing a single component protecting four differential lines. Alternatively, the ULC0342CDNHQ offers Cj=0.22pF (Typ.) in a DFN1006 package, offering more flexible PCB layout.

6  Comparison of pre- and post-upgrade solutions

Differences in typical protection solutions before and after the implementation of CNCA-C11-08:2026 are as follows:

7  EMC component selection list (Leiditech)

The table below summarizes the complete EMC protection component selection recommendations for the CMS electronic mirror system. All ESD/TVS devices are from Shanghai Leiditech and meet AEC-Q101 automotive-grade certification requirements.

8  Summary

The implementation of CNCA-C11-08:2026 marks a new phase for CMS electronic mirror systems, transitioning from "recommended compliance" to "mandatory market access." This means that EMC protection design is no longer an optional "bonus" but a mandatory "entry permit" for product launch.

The key upgrade points for CMS EMC protection solutions before and after the implementation of CNCA-C11-08:2026 are as follows:

· Comprehensive upgrade in protection levels: ESD has been raised from L2~L3 (Category 1) to L3~L4 (Category 1). Transient disturbance protection must now cover all key ISO 7637-2 pulses.

· Component selection must meet automotive-grade requirements: Protection components must pass AEC-Q101 certification. (The Leiditech TVS series recommended in this article all comply with AEC-Q101 certification.)

· Systematic protection architecture: Upgraded from single-point passive protection to a systematic solution encompassing "multi-stage power protection + low-capacitance TVS for signals + common-mode filtering." The Leiditech EMC engineer recommends coordinating EMC strategy from the architectural level during the system design phase.

· High-speed signal protection is a technical challenge: High-speed signals such as GMSL, LVDS, and MIPI require TVS devices to provide ±30kV ESD protection while maintaining extremely low junction capacitance (<0.5pF). Leiditech's ULC series ultra-low capacitance TVS devices perfectly meet this requirement.

It is recommended that all CMS product manufacturers complete EMC protection solution upgrades and pre-testing for all products before August 2026, ensuring that CCC certification tests can be passed as soon as the new regulation takes effect, securing a market advantage. Shanghai Leiditech offers free EMC testing services and design support to help customers successfully complete CCC certification.