As global display technology continues to advance toward 8K 120Hz and even 10K ultra-high resolution applications, the HDMI Forum, Inc. officially announced the HDMI 2.2 specification at CES 2025. This update marks a new milestone for next-generation audiovisual transmission by significantly increasing transmission bandwidth from 48Gbps to 96Gbps.
To ensure the compatibility and stability of the entire AV ecosystem, the HDMI Forum has begun releasing the HDMI 2.2 Compliance Test Specification (CTS) for various device categories—including Source, Sink, and Connector—starting in November 2025.
This article focuses on the Source CTS 2.2 specification released in April 2026, helping manufacturers navigate the critical technical requirements and testing priorities of the high-speed transmission era.
Figure 1: Evolution of HDMI Bandwidth Specifications
1. Toward 96Gbps: New Certification Thresholds for FRL High-Speed Transmission
HDMI 2.2 introduces new Fixed Rate Link (FRL) transmission rates, adding 16, 20, and 24 Gbps levels. Any Source device supporting these FRL rates must comply with the following two requirements:
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Mandatory Support for Uncompressed Video Formats:Devices must support at least one "uncompressed" video format that requires the selected bandwidth to ensure practical application value.
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Category 4 (Cat 4) Connector Certification:Devices must utilize certified Category 4 (Cat 4) connectors to ensure the integrity of high-frequency signal transmission.
Figure 2: Certified Category 4 Connectors
2. Five New Physical Layer (Electrical) Tests
To address the ultra-high bandwidth of FRL 16 / 20 / 24 Gbps, the latest Source CTS 2.2 adds five physical layer tests to verify the stability and quality of high-speed signals at the underlying circuit level:
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HFB1-1：DC Common Mode Voltage for 16, 20, 24 Gbps FRL Rates
Verifies whether the DC bias of each data lane at TP1 complies with the standard. -
HFB1-2：VSE_Max, VSE_min for 16, 20, 24 Gbps FRL Rates
Measures the maximum and minimum single-ended signal voltages for each data lane at TP1. -
HFB1-3：Slew Rate for 16, 20, 24 Gbps FRL Rates
Evaluates the voltage change rate (Slew rate) of the FRL transmitter during signal rise and fall. -
HFB1-5：FRL Rates Above 12 Gbps
Measures the signal frequency or data rate at TP1 to confirm it meets the standard rate accuracy requirements for FRL. -
HFB1-8：AC Common Mode Noise for 16, 20, 24 Gbps FRL Rates
Verifies that the transmitter's AC common-mode noise is controlled within specified limits to mitigate Electromagnetic Interference (EMI) risks.
Note: The HDMI Forum will continue to expand test items for FRL 16 / 20 / 24 Gbps in the future, including Eye Diagram verification, Jitter testing, and FFE Monotonicity tests.
3. Two New Protocol Layer Tests
Beyond electrical verification, the new protocol layer items focus on logical correctness and system stability during high-speed data transmission.
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HFR1-71：Source FRL Protocol – CED Counter Read
Verifies that the Source device reads all bits of the error counter registers within a single SCDC (Status and Control Data Channel) transaction to ensure consistency in error monitoring data. -
HFR1-73：Source QMS-VRR Transition (FRL)
Verifies the protocol behavior during the Quick Media Switching (QMS) and Variable Refresh Rate (VRR) transition process in FRL mode, ensuring a seamless viewing experience for users when switching content.
Embracing the HDMI 2.2 Era
The successive release of HDMI CTS 2.2 specifications throughout 2026 signifies that the 96Gbps ultra-high bandwidth industry has entered the stage of standardized mass production.
As an officially authorized HDMI Authorized Test Center (ATC), Insight Test Labs has taken the lead in supporting the latest HDMI CTS 2.2 testing services. With our comprehensive testing equipment, extensive experience in high-speed signal verification, and deep understanding of the latest specifications, we assist clients in completing product validation efficiently and accelerating their presence in the global high-definition audiovisual market.
