"Converting signals in the analog domain through National's integrated, all-in-one decoder gets rid of all the complex external circuitry or additional chips you'd find in a digital solution," said Erroll Dietz, VP of National Semiconductor's amplifier products group. "Instead, it offers manufacturers an easy way to add component video compatibility without the headaches and errors of current solutions."
The LMH1251's conversion process is done using analog technology via a color-space conversion matrix, eliminating multiple stages of digital implementations. The result is a cleaner, crisper, decoded video image that is superior to alternative approaches that use discrete components, digital products or FPGAs, said National.
The LMH1251 converts video to within 1 percent accuracy based on vector scope analysis, which exceeds the accuracy of current solutions on the market. The device accepts one set of YPbPr inputs and one set of RGB/HSync/VSync inputs. Using the integrated 2:1 MUX and based on the input selected, the output will be either a decoded TV or buffered PC video signal. The LMH1251's RGB path has 400MHz of bandwidth, enabling it to accept up to 1,600 by 1,200 UXGA video resolutions. The output displays the unaltered RGB video signal.
The YPbPr video path has 70MHz of bandwidth. It is equipped with a smart video detection circuit that automatically senses 480i, 480p, 720p, 1,080i and 1,080p video formats, applying the appropriate color-space conversion and outputting the video in a RGBHV format. The company added that the LMH1251 eliminates the need for a microcontroller to choose the proper detection scheme and also saves board space by integrating all the necessary components: a sync processor, a 2:1 MUX and an analog color-space conversion matrix.
Available in a TSSOP-24 package, the LMH1251 is priced at $3.49 in 1,000-unit quantities. Pb-free package options are also available.