The new 3.3 V, four-channel hybrid redrivers may promote HDMI signal integrity for high-fidelity video transmission.

Diodes Incorporated has launched two hybriddriver ICs with integrated display data channel (DDC) listeners to streamline system designs and improve signal quality in HDMI applications.

Hybrid redrivers IC for HDMI applications.

The company designed the devices, the PI3HDX12311 and PI3HDX6311, to compensate for signal degradation on transmission lines, serving as mediators between a source (like a CPU) and a receiver (a display). These products can be used in a myriad of applications, ranging from laptop and desktop computers to DTVs and active HDMI cables.

Purpose-Built for High-Res Video Transmission

While the PI3HDX6311 supports the HDMI 2.0 protocol and achieves multiple data rates of up to 6 Gbps, the PI3HDX12311 supports the HDMI 2.1 protocol and reaches transfer rates up to 12 Gbps. The two devices offer a DC coupling mode for far-end receiver detection. They also leverage pin linking to achieve programmable equalization, flat gain, and output swing.

Block diagram of the hybrid redriver.

The PI3HDX12311 includes a linear mode of operation, enabling data rates of up to 48 Gbps (12 Gbps per channel) and 8K DTV video resolution. The PI3HDX6311 supports flexible signal integrity, with an integrated equalization circuit, linear amplifier, and buffer circuit.

The devices can bolster transmission over increasingly longer cables using their equalization technology, which can reportedly recover weak TMDS signals and minimize jitter while maintaining image quality and reliability. 

Hybrid Modes and Power-Saving Features

Diodes Incorporated refers to these devices as hybrids because they can operate in two modes: limited or linear.

The devices act as limited redrivers in HDMI 1.4 applications. In this mode, the swing setting can pre-define the differential output swing to maintain HDMI-compliant levels at the receptacle. For HDMI 2.0 and 2.1 applications, the redrivers can be put into linear mode to act as a trace canceller when the output swing is directly proportional to the received signal. Linear mode is also transparent to link-training signals. The redrivers enable input and output signals (or a mixture of both) to be AC or DC coupled, with a short-circuit detection feature in DC-coupled mode. 

The PI3HDX12311 and PI3HDX6311 drivers can monitor the hot plug detection (HPD) pin, located on the connector, to minimize power consumption. The devices switch to a low-power state when the HPD is low for more than 2 ms. The devices' DDC listeners also oversee the status and control data channel structure (SCDCS) offset registers and the HDMI Forum Vendor Specific Data Block (HF-VSDB) to keep power consumption low. 

Boosting Resolution for Video Signals

Diodes designed the new hybrid driver ICs to meet the demands of high-resolution video transmission, making it easier to design systems for HDMI applications. The company has identified several use cases that may benefit from the two new redrivers, including DTV and commercial display panels, desktop PCs, laptops, docking stations and peripherals, and gaming consoles, among others.

These devices may enable longer transmissions with multiple data rates for such applications, paving the way for future HDMI systems that require high signal integrity.

All images used courtesy of Diodes Incorporated.