Knowledge base
USB Connectors and Data speed
*reference from USB standard
USB Logos - All the different types
*reference from USB standard
USB Cable Maximum Length - Data considerations
USB-IF standard recommended below length for USB cables for data transfer
*reference from USB standard
USB Cable Maximum Length - PD Charging considerations
USB Power Delivery (PD) standard recommended below length for USB cables
*reference from USB standard
USB Cable PD Charging - EPR vs SPR
USB Power Delivery (PD) power range specifications for USB cables. In the fixed voltage scheme, the Standard Power Range (SPR) mode supports 3A and 5A at 5V, 9V, 15V, and 20V. The 3A configuration supports between 15 and 60W. The 5A scheme requires a specific type of cable and can supply up to 100W. The new Extended Power Range (EPR) mode supports all voltage and current combinations of SPR, and also includes 5A supply at 28V, 36V, and 48V, allowing for support up to 240W.
*reference from USB standard
USB Cable Bandwidth Data speed - Bit vs Bytes
Data speed of different USB versions - 1 Byte = 8 Bits, 1 Kilobyte (KB) = 1024 Bytes
*reference from Wikipedia
DisplayPort 2.1 UHBR Modes
*reference from VESA
DisplayPort and HDMI Resolution / Bandwidth
Digital Video Resolution/ fps vs Data Rate Bandwidth
What can go wrong with cheap inferior AOC cable?
Compatibility - Inside the connectors, there is a chipset inside. Some inferior VCSEL laser dies after short period of time. The chipset is responsible to make sure the TV (Display side) and DVD ( Source side ) EDID reading successful, then image can show on the Display. If the Chipset is not designed properly to match most Display and Source on the market, there will be compatibility issue. There is no fix in this situation. A lot of factory to pursue low cost and used low quality chipset. These chipset can only work with limited Display and Source, so often have compatibility issues. If the cable is not working after installation, it is much more expensive in labor to replace the cable.
Broken Optical Fiber - since this inside cable is fiber optic, it is very very fragile. Therefore, the filler material inside the cable is very important in protecting your cable. The right material is kevlar, but many cheap cables uses cotton or nylon. Cable installation is a rough process pulling cables through conduits. Inferior filler material CANNOT protect your fiber during installation. If the cable is broken during installation, it is much more expensive in labor to replace the cable
Broken Connection - since this inside cable is fiber optic, and connected to the connector module. This is very precision assembly technique. Slight misalignment on the fiber/module connection can result in a non-working cable. Therefore, not only the fiber/module connection needs to be done right, it also needs to be protected properly. Cable installation is a rough process pulling cables through conduits. Poor fiber connection CAN BREAK during installation. If the cable is broken during installation, it is much more expensive in labor to replace the cable.
Missing ARC support - In an HDMI AOC cable, there are copper wires for communication protocols: one for power supply, one for CEC, two for audio return (ARC), and one for DDC signals. A lot of factory pursue low cost and remove the 2 copper wires for ARC.
Durability and life expectancy - Inside the connectors, there are VCSEL lasers that emits optical signals into the fiber. Some inferior VCSEL laser dies after short period of time. If one of the VCSEL fails, the cable do not work at any device. There is no fix in this situation. A lot of factory pursue low cost and used low quality VCSEL, these are high risk defective. If the cable is broken after installation, it is much more expensive in labor to replace the cable.
Common cable abbreviations
Conductor
BC - Bare Copper
TC - Tinned Copper (solid)
TS - Tinned Copper (stranded)
CCS - Copper Clad Steel
CCA - Copper Clad Aluminum
#C - number of conductors
#P - number of pairs
#PCS - number of wire sets
Shielding
D - Drain
Al - Aluminum Foil
MY - Mylar Film
B - Braiding
AEB - Aluminum Earth(drain) and Braiding
Cable Jacket
LSZH/LSOH - low smoke zero halogen
Common UL flammability cable ratings
AWM (Appliance Wiring Material)
This type of wire is defined by UL 758, and is meant to be used with consumer products in basic connectivity applications, such as connecting a computer to a monitor, or routing a USB cable from a motherboard to the outside of the computer case. AWM wire is not meant to be used in building installations, unless it is within the scope of the installation instructions for a particular product (5). However, there is some overlap in test scenarios between UL 758 and UL 13 (which covers CL2, CL2X, and CL3).
VW-1 (Vertical Wire 1) - ANSI / UL 1581
The VW-1 (Vertical Wire Flame Test) is a flammability test used to evaluate the fire resistance of electrical wires and cables. The test determines whether a material can withstand exposure to a small flame without spreading the fire. Here’s a brief overview of the process:
Test Setup: A wire or cable specimen is mounted vertically, and a controlled flame is applied directly to it for a specific period (usually 15 seconds, with break of 15-60s). A paper flat is attached to the top end of the wire.
Criteria: After the flame is removed, the material is observed for flame spread, burning time, and whether or not it emits burning particles. The goal is for the specimen to self-extinguish without dripping molten material that could ignite other objects such ast the paper flag.
Passing the Test: For the cable to pass, it must not exceed a certain length of flame spread and must self-extinguish within a specific time frame. No flaming particles or dripping that would ignite a cotton pad placed below the test sample are allowed.
VW-1 is one of the standard tests used to certify cables for safety in environments where fire hazards are a concern, such as in building wiring or electronics.
CL2 (Class 2) - ANSI / UL 1685
This is one type of mark that is given to cables that meet the UL 13 "Power-limited Circuit" standard, which is designed to test the safety of cables when they are installed in buildings. CL2 uses a different test methodology than VW-1 that includes both burning and smoke. The test scale is also larger-scale than VW-1, incorporating a tray instead of a single section of wire.
CL2X and CL3
CL2X and CL3 are both cable ratings defined by the National Electric Code (NEC) and certified by Underwriters Laboratories (UL). They indicate the intended use and maximum voltage these cables can safely carry, particularly in low-voltage applications such as home automation, audio, and video systems.
CL2X
Definition: CL2X cables are designed for low-voltage use, specifically for residential environments.
Voltage Rating: These cables can carry up to 150 volts.
Usage: They are intended for use within dwellings, such as inside walls or ceilings, and are part of the "dwelling" classification. CL2X cables have less stringent flame-resistance requirements compared to their CL2 counterparts and are typically used in areas where building codes allow less demanding flame testing.
Restrictions: CL2X cables are limited to residential installations and cannot be used in the same wide range of locations as general-purpose CL2 cables.
CL3
Definition: CL3 cables are designed for general-purpose low-voltage applications.
Voltage Rating: They can carry up to 300 volts, making them suitable for more demanding installations than CL2 or CL2X cables.
Usage: These cables are often used in commercial and residential settings, including inside walls and conduits. CL3 cables are more robust, with higher fire-resistance standards, and can be used for systems that require higher power transmission, such as security systems, intercoms, and alarm systems.
Flexibility: A CL3 cable can be used in any location where a CL2 or CL2X cable is allowed, providing more flexibility for installations across various environments.
In summary, CL2X cables are more limited to residential, low-power applications, whereas CL3 cables are more versatile, with higher voltage ratings and stricter fire safety requirements for both commercial and residential installations.
What is Trade Agreement Act (TAA)
TAA refers to the Trade Agreements Act (19 U.S.C. § 2501—2581)
According to the Buy American Act (BAA), contractors in the United States who supply products for GSA Schedules and other government contracts, are required to give preference to products from countries Trade Agreements Act (TAA) designated countries. As a manufacturer in TAA designated country, Taiwan, most of HCI’s products are eligible for procurement by the U.S. government.
The TAA is intended to foster fair and open international trade by implementing international trade agreements and governs the procurement of goods and services by the federal government. TAA compliance requirements are built into U.S. federal procurement contracts such as GSA (General Services Administration) Schedule contracts, IDIQ (Indefinite Delivery, Indefinite Quantity) contracts and most DOD (Department of Defense) contracts.
As a Taiwan based manufacturer, Skycable has numerous products which are made in Taiwan, and complied with TAA regulations. Please contact us for more information.
Contact Us
SKYCABLE ENTERPRISE CO., LTD.
1F., No. 89, Yongji Rd., Xinyi Dist., Taipei City ,Taiwan
(post code:11070)
TEL:+886-2-27661655