The HDMI 2.1 connector has seen numerous updates in electrical and physical performance parameters compared to the HDMI 1.4 version. Let's delve into each of these updates:
1、Increased High-Frequency Testing for HDMI Connectors:
As the demand for high data rate transmission, especially for 4K and 8K Ultra HD (UHD) TVs, rises, HDMI becomes crucial for reliable data transfer between the source (video player) and the receiver (TV). With higher data rates, the interconnect between these devices becomes a bottleneck for reliable data transmission. This interconnectivity may lead to Signal Integrity (SI) issues such as Electromagnetic Interference (EMI), crosstalk, Inter-Symbol Interference (ISI), and signal jitter. Consequently, with the rise in data rates, HDMI 2.1 connector design has started to consider SI. As a result, the association testing has added requirements for high-frequency testing. To enhance the SI performance of HDMI connectors, connector manufacturers have modified the shapes of metal pins and dielectric materials according to design rules and mechanical reliability to meet the high-frequency testing requirements.
2、Increased Bandwidth Requirements for HDMI 2.1 Connectors:
The previous HDMI 2.0 had a throughput of 18Gbps but did not define new HDMI cables or connectors. HDMI 2.1, on the other hand, boasts over double the throughput, allowing for bandwidths of up to 48 Gbps. While new HDMI 2.1 cables will be backward compatible with HDMI 1.4 and HDMI 2.0 devices, old cables won't be forward-compatible with the new specifications. HDMI 2.1 connectors feature four data channels: D2, D1, D0, and CK, through which data is transmitted differentially. As each channel shares similar electrical characteristics, HDMI 2.1 connector designs need to exhibit superior SI performance to meet the 48Gbps bandwidth of the next-generation HDMI connector.
3、Additional Differential Requirements:
HDMI 2.1 connector testing falls under Category 3, whereas HDMI 1.4 testing falls under Category 1 and Category 2. After HDMI 2.1, connector shapes are limited to Type A, C, and D, with the previously-used Type E interface primarily in the automotive field being phased out. To enhance electrical characteristics to meet HDMI 2.1 standards, connector designs require modifications to design parameters such as the width, thickness, and length of metal pins. Some manufacturers may also employ other methods, such as introducing gaps in the socket's dielectric material, to reduce capacitance coupling. Ultimately, the validated design parameters need to meet impedance ranges. HDMI 2.1 connectors offer better SI performance than previous lower-tier versions, and corresponding connector manufacturers will implement various device and process controls.
