Introduction

The USB-IF offers a Qualification by Similarity program to member companies that allows certain products to be granted USB certification or EU conformity to IEC 62680 status and be placed on the USB-IF Certified Products and Integrators List and/or the EU Conformity to IEC 62680 List with limited or no compliance testing.   The QbS program enables a new USB connector, cable, charger, peripheral, host or hub that is substantially similar to a fully tested and certified USB product to be granted certification based on its similarity to the originally certified product.   In the same process it allows an external power supply or portable battery powered device that is substantially similar to a fully tested EU conformity product to be granted EU conformity to IEC 62680 status based on its similarity to the original product. The purpose of the QbS program is to speed time-to-market and to minimize certification costs.   It is not intended to eliminate the requirement that a product pass USB-IF compliance or meet EU conformity to IEC 62680 testing.

The only authority to grant Qualification by Similarity to a product is the USB-IF.   No test facility or any other entity is authorized to grant or pursue Qualification by Similarity requests on behalf of the USB-IF.   The qualifying product must be similar to a USB certified or EU conformity product that has undergone full and complete USB-IF compliance or EU conformity to IEC 62680 testing.   The qualifying product cannot be compared to another product that itself has been granted Qualification by Similarity.   The certified product, otherwise known as the base or parent product in a QbS submission, cannot be older than 2 years old. Exceptions are made for host silicon, hub silicon and automotive specific hubs and embedded hosts, which have an age restriction of 3 years. There is currently no age restriction for base/parent EU conformity products as the program has only recently been released.

NOTE: Connectors and Cable Assemblies, due to their simplicity, may base the similarity on a product that itself has been granted QbS.  Also, the age of the certification of the base connector or cable assembly is not limited to 3 years.

Modifications to the qualifying product are not allowed after submitting a Qualification by Similarity Request to the USB-IF.

Below is a general description of the Qualification by Similarity process:

1. Member companies submit a Qualification by Similarity request using the form available at http://compliance.usb.org/QbS/.
2. If applicable, the USB-IF will request specification sheets/drawings/Vendor-Information-Files of both the originally certified and new products.
3. A review of the QbS request and specification sheets/drawings/Vendor-Information-Files will be performed by the USB-IF.   One or more of the authorized test labs, USB specification editors and/or other USB-IF member experts in a given field may be consulted.
4. The USB-IF will issue its assessment to the vendor. One of three outcomes is possible:
• Qualification by Similarity is granted and no other action is required. A new TID will be issued to the new product
• Qualification by Similarity is denied. All certification or EU conformity to IEC 62680 tests are required for the new product
• Qualification by Similarity may be granted provided the new product passes a subset of specific compliance tests
5. If the assessment requires passing a subset of compliance tests, the vendor will be informed of the required tests in an email from the USB-IF that includes a QbS ID number
6. The vendor has 90 days to submit the product for testing to the authorized test lab of their choice along with a copy of the email
7. The test lab should request a copy of the specification drawings from the USB-IF to verify that the product submitted for testing matches the drawings.   Please use the QbS ID number when requesting the drawings.
8. The authorized test lab performs only the tests identified in the email
9. Upon successful completion of the tests, the authorized test lab will send an email to TechAdmin@usb.org along with the test results and the QbS ID number.
10. If the product passes all required tests, then the USB-IF will grant Qualification by Similarity to the product, issue a TID number and add the product to the Integrators List.

    NOTE: Should the qualifying product fail any required compliance test, the authorized test lab must immediately notify the USB-IF of the failure where the product is automatically denied USB-IF certification or EU conformity to IEC 62680 status and becomes ineligible for the Qualification by Similarity program.   In order to obtain USB-IF certification or EU conformity to IEC 62680 status, the qualifying product will have to satisfactorily complete the entire compliance test program for its category.   In addition, the USB-IF may require the base (parent) product to undergo a compliance audit at the vendor’s expense.

Requirements for Retest

The qualifying product must be derived directly from the USB-IF certified or EU conformity product with only minor changes.   If any changes are made that would create "significant differences" between the USB-IF certified or EU conformity product and the qualifying product then retesting is required.  The definition of "significant differences" is sometimes debatable and the final judgment is the responsibility of the USB-IF Compliance Review Board which reports to the USB-IF Board of Directors. 

Notable decisions on what is considered a "significant difference" will be listed here.  The following guidelines posted below are not comprehensive.  The ultimate responsibility for making sure that the production product matches the product samples submitted for compliance testing lies with each vendor.  Audits by USB-IF that reveal discrepancies between shipped products and samples tested may be cause for required re-test, revocation of USB-IF certification and/or EU conformity to IEC 62680 status, and/or legal action.

It is recommended that the most full featured and power demanding version of a product be tested for USB-IF certification or EU conformity to IEC 62680 status.  Removing features, functions and depopulating components are more likely to be granted QbS than otherwise.

Significant Difference Guidelines

Devices (Peripherals, Hosts, Hubs, Embedded Hosts, etc.)

Retest Typically Not Required

• Aesthetic changes to the product's housing (such as color)
• Changes to the product's packaging (color, shape, etc.)
• Microcontroller firmware change (changes in fully modular code not associated with USB functions)
• Microcontroller change to another certified microcontroller (no PCB layout change, no firmware change)
• USB connector change to another certified connector (no PCB layout change)
• Removal of modular features (no PCB changes)

Retest Typically Required

• Any change to the PCB where USB circuitry resides (trace widths, trace layout, components added, etc.)
• Addition of USB functions

Silicon

Retest Typically Not Required

• Removal of features via bond options or fuse options
• Package change within the same package family

Retest Typically Required

• Metal steppings
• Die changes
• Package family change

Note: Chipset Design Changes.

Chipsets are modular in nature and changes in one module are unlikely to affect the IP in a different module. Changes to chipsets that are unrelated to USB still require testing, but the tests are limited to validating signal quality of USB. There is no need to validate protocol timings related to packets.

Connectors

 

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