As 32" 720P LCD TVs move under $500 and 17" PC monitors head below $100, TV, PC, monitor and panel makers must find ways to both differentiate and add value. Avoiding "commodity" status is connected to both increasing demands on video/graphics processors, and handling greater bandwidth requirements for interconnects that transport burgeoning amounts of data. Here are seven ways to differentiate next-generation panels:
- Address size, resolution, wide color gamut and deep color requirements
- Optimize cost
- Control electromagnetic interference (EMI)
- Enable lower power operation
- Increase frame rate
- Deliver wireless high definition
- Provide a full digital experience
Size, resolution and color
Larger size, high resolution, wide color gamut, and deep color all require higher bandwidth in both the internal and external bus. Consider the external bus cable medium between the DVD and TV. Increased bandwidth can be observed at the high definition media interface (HDMI). An older HDMI 1.1 standard supported only 8 bits per color (pbc) while requiring approximately 1.65 Gbps of link speed. In comparison, today's HDMI 1.3 standard needs 2.25 Gbps link speed in order to support 10 bpc.
The increased demand for bandwidth also affects the internal bus such as the link from the TV system controller board to an LCD panel controller board. The traditional LVDS technology link is becoming a bottleneck for the huge amount of data delivered by the external bus. In this case, two sets of four pair LVDS are necessary to support Full HD resolution (1080p).
In response, a new display standard, DisplayPort based on SerDes technology is making inroads to addressing the bandwidth pressures posed by new requirements. One 8-wire DisplayPort implementation replaces a 32 x 4 LVDS link in terms of bandwidth. Featuring 10.8 Gbps of bandwidth over four links, DisplayPort is adequate to satisfy high resolution and deep color performance challenges. In PC applications its benefits are more obvious--it has the ability to optimize the display by driving resolution size of the panel from the GPU.
In TV applications, the external connection to the set top box is HDMI and the internal bus connection is DisplayPort. Both mediums can coexist and complement each other in this environment.
Optimizing cost
Integration is the key to cost optimization. The processor today integrates such I/O functions as HDMI, ADC for external analog components, LVDS interfaces, post image processing, and the tuner. New interface standards including DisplayPort enable direct drive for monitors eliminating the scalar processor and control board. The native resolution of the panel is enhanced, decreasing overall system cost and increasing performance by simply removing unnecessary steps in image compression and manipulation.
Control EMI
As resolution size and color depth increase, the system requires greater speed from its system clock and pixel clock. The drawback of increasing the frequency, however, is that it results in greater electromagnetic interference (EMI). There are strict requirements for EMI and given increased bandwidth, even greater EMI control is necessary.
New standards solve this problem as part of the specification, yet the challenge is at the system level. Mature phase locked loop technology with best-in-class spread spectrum generation and degeneration are necessary to reduce EMI and keep it under control.
Next: Manage power, Increase frame rate
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