NATIONAL Semiconductor, represented in Australia by Arrow Electronics , has released a point-to-point differential signalling digital interface architecture and chipset for LCD TVs.
The PPDS architecture enables cinema-quality display performance and smaller bezels. It can support LCD TVs up to 90” in diagonal. The architecture also simplifies the design of the intra-panel interconnect, reducing the number of column driver input signals by up to 50%.
The architecture combines a physical layer interface with high-level protocol to reduce the overall printed circuit board size. It is capable of delivering more than one billion colours to the display for 30-bit colour. It can drive panels of up to 90” at resolutions up to 1920 x 1080 lines.
National also has developed a timing controller and column driver to support the PPDS architecture. The FPD80200 timing controller uses the industry standard FPD-Link input to receive video data and a PPDS interface output for communication with the column drivers. Its data manipulation algorithms create cinema-quality video images. Unlike traditional panel driving schemes, the gamma conversion occurs in the timing controller instead of the column driver. This enables digitally programmable and independent gamma curves for red, green, and blue.
The FPD80200 operates off a 2.5V digital supply for lower power and lower EMI, but includes 3.3V I/O cells to be compatible with typical gate driver ICs. All of the functions of the timing controller can be programmed with an external EEPROM for rapid prototype and product development.
The FPD48084 column driver receives data via the PPDS interface and uses a linear DAC to convert the incoming data to the appropriate output voltage. The column driver also operates at a 2.5V digital supply. Because the column driver uses a linear DAC instead of the traditional non-linear R-DAC, the total number of reference voltages needed for the gamma curve has been reduced from 18 to six.