SerDes chips provide a low EMI and high performance to automotive LCDs

July 02, 2013 // By Paul Buckley
Texas Instruments has expanded its FPD-Link III automotive-grade SerDes family today with the industry’s most feature-rich chipset.

The DS90UH927Q-Q1 serializer and DS90UH928Q-Q1 deserializer deliver uncompressed high-definition (HD) digital video and audio to touchscreen LCD panels in a vehicle’s central information display and rear passenger seats. The DS90UH928Q-Q1 is the industry’s only deserializer to offer automatic cable equalization, 24-bit color dithering, and white balancing over an LVDS connection. These features enable LCD panels to provide the highest performance, lowest cost, and lowest electromagnetic interference (EMI), compared to competitive solutions.

The chipset supports high-bandwidth digital content protection (HDCP), and a direct connection to LVDS input sources and displays, including the OpenLDI (LVDS digital interface) standard. This reduces the number of signal lines by 68 percent and makes them differential to provide the lowest possible EMI. Compared to the competition, TI’s FPD-Link family gives system architects a greater number of video sources and displays that can be directly connected to the automotive video network.

The 5-MHz to 85-MHz pixel clock and 24-bit pixel depth combine with on-chip white balancing, high frame rate control dithering, and 7.1 audio support to deliver high-quality video and sound. This provides a consistent look across all car models from entry-level sedans to luxury sport utility vehicles (SUVs). The dithering and white balancing feature at HD resolution also saves costs by allowing the use of lower quality LCD panels.

The: DS90UB928Q-Q1 adapts automatically to the cable length and the condition or age of the cable. This unique feature addresses cable wear and tear that often occurs with drop-down or pop-up displays, and allows manufacturers to stock fewer LCD panel versions.

The devices carry digital video, audio and bidirectional I2C control signals concurrently over a single twisted wire pair using the HDCP interface protocol. HDCP and encrypt/decrypt keys are implemented in the SerDes on-chip memory, simplifying system design. This eliminates the cost of microcontrollers and FPGAs that are required with packet-based, compressed video systems using an Ethernet interface.

The DS90UH927Q-Q1 and DS90UH928Q-Q1 can be mixed and matched