Key Points for MIPI High-Speed Cable Selection: How to Achieve the Best Match Between Interface and Thin Coaxial Cable

With the continuous improvement of the performance of smartphones, vehicle displays, tablets, and image sensor modules, MIPI (Mobile Industry Processor Interface) has become the mainstream interface standard for high-speed image data transmission. In high-speed links, the matching of extremely thin coaxial cables with extremely thin coaxial connectors such as I-PEX, HRS, JAE, KEL directly affects the signal integrity, EMI performance, and structural reliability of the system.
This article combines practical engineering experience to summarize the key points that need to be focused on when selecting MIPI signal cable and interface.

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One, impedance continuity is the foundation of high-speed links.

MIPI D-PHY and C-PHY both impose strict requirements on differential impedance (commonly 90Ω±10%). Extremely thin coaxial cables, due to their fine wire diameter and thin dielectric, are susceptible to impedance discontinuity caused by any changes in shielding structure or dielectric deviation, leading to reflections and eye diagram distortion. Therefore, when selecting, it is necessary to clearly define the target impedance of the connector series (such as I-PEX 20455, 20373, etc.) and ensure that the impedance path between the connector, cable, and PCB remains continuous. Impedance control is the first prerequisite for the reliability of high-speed links.

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The shielding structure and EMI performance must match the interface design.

MIPI signal rates can reach several Gbps, with high risks of high-frequency noise and crosstalk. Many I-PEX and HRS interfaces have a metal shell grounding structure. If the cable harness only uses a single layer of shielding or the shielding coverage is insufficient, it will cause EMI leakage and differential crosstalk. Therefore, in MIPI applications, it is recommended to prioritize the use of extremely thin coaxial cables with double shielding (copper foil + braid) to ensure a complete and continuous grounding path to the interface terminal, thereby effectively reducing system electromagnetic interference.

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Three, structural design, insertion and extraction life, and processing consistency are equally critical.

High-speed harnesses must not only meet electrical performance requirements but also take into account structural space, durability, and manufacturing processes. In terms of harness length, MIPI D-PHY is generally recommended not to exceed about 150mm under 1.5Gbps conditions; if length is limited, low-loss media (such as FEP, PTFE) should also be selected. In terms of reliability, there are significant differences in the locking method of connectors and the number of insertion and extraction times, such as I-PEX 20879 which has a locking clip structure and can meet high-frequency insertion and extraction requirements. On the processing level, shielding termination, crimp depth, grounding tab length, and other factors all directly affect impedance consistency, and it is necessary to choose harness manufacturers with precise processing capabilities to ensure stable quality.

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MIPI High-speed signal design is a systems engineering discipline, involving multidimensional factors such as impedance, electromagnetic compatibility, mechanical structure, and production technology. High-quality ultra-fine coaxial cable bundles and appropriate matching interfaces are the core of stable transmission of high-speed camera and display data. By selecting the correct cable structure, shielding method, interface type, and ensuring processing consistency, engineers can achieve ideal signal integrity and system reliability in high-speed environments.

I amSuzhou Huichengyuan Electronic TechnologyLong-term focus on the design and customization of high-speed signal cable harnesses and ultra-fine coaxial cable assemblies, committed to providing stable and reliable high-speed interconnect solutions. For more information, please contact us.Yin Manager: 18913280527 (same WeChat number)。