How to Identify the Quality of LVDS Cables?

In the market for LVDS (Low-Voltage Differential Signaling) Cables, products vary drastically in quality—from industrial-grade cables that deliver reliable performance for years to cheap, substandard options that fail within months. Choosing a low-quality LVDS Cable can lead to signal interference, device damage, or costly downtime, especially in critical applications like medical imaging or industrial automation. To avoid these risks, it’s essential to know how to distinguish between high-quality and inferior LVDS Cables. Below is a detailed, practical guide to evaluating LVDS Cable quality, covering visual inspections, material checks, performance verification, and brand/certification validation.

• High-quality cables: Have a smooth, uniform jacket with no bubbles, cracks, or uneven thickness. The jacket material (e.g., PVC, polyurethane) feels durable—not flimsy or sticky. Brand logos, model numbers, and specifications (e.g., “100Ω ±10%”) are printed clearly and do not rub off easily.

• Inferior cables: Have rough, uneven jackets with visible defects (e.g., pinholes, bumps). The print is blurry, smudged, or peels off when rubbed with a finger. Some cheap cables may even lack printed specifications entirely.

• High-quality connectors: Have gold-plated pins (gold resists corrosion and ensures low contact resistance). The pins are straight, evenly spaced, and free from bends, scratches, or oxidation (no green/brown discoloration). The connector housing is sturdy, with no loose parts or gaps, and locks securely into the port with a firm “click.”

• Inferior connectors: Use tin-plated or even unplated pins (prone to corrosion). Pins may be bent, misaligned, or missing. The housing is often made of cheap plastic that feels brittle, and the locking mechanism may be loose or non-functional.

• High-quality cables: Are flexible but retain their shape—they do not kink or crack when bent to the minimum bend radius (specified in the datasheet). The cable feels balanced, with no lumps or unevenness (indicating uniform internal components).

• Inferior cables: Are either overly stiff (due to thick, low-quality insulation) or excessively floppy (due to thin conductors). Bending them may reveal lumps (signaling uneven twisting of the differential pair) or cracking of the jacket.

• How to distinguish:

1. Weight: Copper is denser than aluminum— a high-quality 10-meter LVDS Cable will feel heavier than a CCA cable of the same length and gauge.

1. Magnet test: Aluminum is non-magnetic, while copper is slightly magnetic. Use a small magnet (e.g., a fridge magnet) to test the conductor (you may need to strip a tiny section of insulation). If the magnet sticks weakly, it’s copper; if it doesn’t stick, it’s likely CCA.

1. Solderability: Tinned copper solders easily, while CCA often forms a weak joint (inferior cables may avoid soldered connections altogether).

• High-quality shielding: Uses either foil (aluminum or copper) with 100% coverage, braided copper (with 85%+ coverage), or dual shielding (foil + braid). The shield is securely attached to the connector (no gaps) and does not peel away from the insulation.

• Inferior shielding: Uses thin, partial foil (with gaps) or loosely woven braids (coverage <70%). The shield may be disconnected from the connector or tear easily when touched.

• High-quality insulation: Uses materials like polyethylene (PE) or ethylene tetrafluoroethylene (ETFE), which have stable dielectric properties (ensuring consistent impedance). The insulation is thin but durable— it does not crack when bent or melt at moderate temperatures (e.g., 60°C).

• Inferior insulation: Uses recycled PVC or low-grade plastics, which have inconsistent dielectric properties. The insulation may be thick (to hide thin conductors) or brittle, cracking easily when bent.

• Impedance: Should be 100Ω ±10% (the industry standard for LVDS). Avoid cables with unspecified or inconsistent impedance (e.g., “90–120Ω”).

• Signal skew: Should be <30 picoseconds (ps) for high-speed applications (1 Gbps+). Low-quality cables may not list skew or claim values >50 ps.

• Attenuation: Should be <0.5 dB/meter at 1 GHz. Cables with attenuation >1 dB/meter will suffer significant signal loss over distance.

• Essential certifications:

• CE (Conformité Européenne): Ensures compliance with EU EMC and safety standards.

• UL (Underwriters Laboratories): Certifies fire safety (e.g., UL 94 V-0 for flame retardancy) and electrical performance.

• RoHS (Restriction of Hazardous Substances): Confirms the cable is free of lead, mercury, and other toxic materials.

• Application-specific certifications:

• For automotive use: ISO 10605 (EMC testing) or IATF 16949 (quality management).

• For medical use: IEC 60601 (safety for medical devices).

• Set the multimeter to “continuity” mode (it beeps when there is a complete circuit).

• Connect one probe to a pin on the cable’s male connector and the other to the corresponding pin on the female connector.

• A beep indicates a continuous conductor (good); no beep means the conductor is broken (bad).

• Also, test for shorts: touch probes to two different pins—no beep means no short (good); a beep indicates a short circuit (bad).

• Signal skew: Connect the oscilloscope to the positive and negative pins of the differential pair—skew is the time difference between the two signals. It should be <30 ps.

• Attenuation: Measure the signal amplitude at the transmitter and receiver ends—attenuation is the percentage of signal lost. It should be <5% over 10 meters at 1 GHz.

• Reputable brands: Companies like Molex, TE Connectivity, Samtec, and Hirose have a long history of manufacturing high-quality LVDS Cables. They provide detailed datasheets, honor warranties (1–5 years), and offer technical support.

• Inferior brands: Unknown or generic brands (often sold on discount platforms) lack brand history, provide no warranties, and disappear quickly if issues arise.