I-PEX 20680-040T-01 High-Speed Connector and Extremely Thin Coaxial Cable Assembly Application Analysis

In the current industry trend of high integration and high-speed transmission, the interconnection methods within devices are facing more stringent requirements for space and performance. As a representative model of high-speed miniature coaxial connectors, I-PEX 20680-040T-01 boasts its reliable structural design and powerful transmission capabilities, widely used in laptop computers, tablet devices, wearable products, drones, and in-vehicle systems. The micro coaxial cable that pairs with it is the key foundation for ensuring stable high-speed signal transmission.
In order to help engineers better understand the relationship between harness length, bend radius, and overall performance, this article will comprehensively analyze from the design perspective in combination with I-PEX 20680-040T-01.



 

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Introduction to I-PEX 20680-040T-01 connector

I-PEX 20680-040T-01 belongs to the CABLINE®-CA II series, a miniature coaxial connector developed for high-speed signal links. Its miniaturization, shielding, and high-speed capability make it a core interconnection component for many precision electronic devices.

Main features are as follows:

1. Pitch and pin count: Designed with a 0.4 mm pitch, providing a 40-pin layout, suitable for high-density PCB connections.

2. Insertion and extraction method: Horizontal insertion and extraction structure, with a thinner overall thickness, suitable for precision modules with limited space.

3. Shielding Structure: Apply ZenShield comprehensive shielding design, combined with multi-point grounding method, effectively reduce EMI leakage risk, and enhance the system's anti-interference capability.

4, Transmission capability: Supports up to 20 Gbps/lane, compatible with high-speed protocols such as Thunderbolt 3, USB4, and eDP HBR3.

Adaptable cables: compatible with ultra-fine coaxial cables from AWG 38 to AWG 46, providing a stable physical path for high-speed signal transmission.

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The relationship between the length of ultra-fine coaxial cable束 and its transmission performance

Micro coaxial cable has the advantages of extremely small diameter, low loss, and strong anti-interference ability, but the cable length has a significant impact on its performance.

The influence of length on attenuation

The longer the cable, the more obvious the signal attenuation becomes, and it will also generate higher transmission delay. When the length exceeds the recommended value, such as more than about 500 mm, the attenuation curve will rise sharply, which is detrimental to high-speed links.

2, length and impedance matching

It is more difficult to maintain consistent impedance along longer paths, especially in high-speed eDP/MIPI signals, where impedance fluctuations can cause echo distortion and eye diagram degradation.

3. Recommended App Length
For high-speed applications such as eDP, MIPI, and USB4, it is recommended to control the total length of the cable束 within the range of 200 mm to 300 mm, which can effectively ensure stable signal quality.

 

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The effect of bend radius on high-speed signal links

Extremely thin coaxial cables are flexible and bendable, but a small bending radius is prone to cause a decrease in electrical and structural performance.

Impedance discontinuity

Bending too sharply will change the geometric shape of the coaxial structure, causing an abrupt change in impedance, resulting in phenomena such as signal reflection and distortion.

Risk of mechanical damage

The internal conductor is prone to fatigue or breakage when excessively bent, affecting its service life.

Recommend bending radius
Normal usage: Bend radius ≥ 5 mm
High-speed signal link: bend radius recommendation ≥ 10 mm

High-speed harnesses compatible with I-PEX 20680-040T-01 should follow this standard more strictly to ensure stable and reliable long-term operation.

I-PEX 20680-040T-01 stands out in modern electronic devices with its miniaturization, high-speed transmission, and full shielding structure. The matching micro coaxial cable can only maintain excellent signal integrity in high-speed applications when the cable length, bend radius, and impedance consistency are reasonably controlled. For products pursuing thin and high-speed designs, standardized cable design and appropriate connector selection are indispensable.

I amSuzhou Huichengyuan Electronic Technology,Long-term focused on the design and customization of high-speed cable harnesses and ultra-fine coaxial cable harnesses, committed to providing customers with stable and reliable high-speed interconnection solutions. For information on cable harness processing, connector selection, or high-speed signal solutions, please contact:Manager Yin 18913280527 (same WeChat number)。