Datasheet LT6550, LT6551 (Analog Devices) - 14
| Manufacturer | Analog Devices |
| Description | 3.3V Triple and Quad Video Amplifiers |
| Pages / Page | 16 / 14 — TYPICAL APPLICATIO. RGB to YPBPR Component-Video Conversion |
| File Format / Size | PDF / 311 Kb |
| Document Language | English |
TYPICAL APPLICATIO. RGB to YPBPR Component-Video Conversion
Model Line for this Datasheet
Text Version of Document
LT6550/LT6551
U TYPICAL APPLICATIO
Consumer products require generation of YPBPR lumi- the desired unity gain is produced for the Y-channel. The nance/chrominance component signals, often from RGB necessary scaling of the color-difference signals is per- source content. The YPBPR format has a luminance signal formed passively by their respective output termination and two weighted color difference signals at baseband. resistor networks. Since this circuit naturally produces Even with their fixed internal gain resistors, two LT6550s bipolar chroma signals (±0.35V at the cable load) regard- connected as shown easily implement the required con- less of RGB offset, the simplest implementation is to version matrix equations. The Y channel is a weighted power the circuit with ±3.3V split supplies. With an avail- average of the 2X amplified RGB signals and with the able output swing of about 5.6V for this supply configura- feedback connection of the Y channel output in the second tion, the circuit handles video with composite syncs and/ LT6550 back to the gain-resistor common pin, an implicit or various offsets without difficulty. Y subtraction is performed for the chroma channels and
RGB to YPBPR Component-Video Conversion
3.3V 3.3V LT6550 10 LT6550 10 450Ω 450Ω 450Ω 450Ω – 9 1070Ω – 9 105Ω 1 P 1 R R + + 261Ω 75Ω 450Ω 450Ω 450Ω 450Ω – 8 549Ω – 8 75Ω Y 2 2 G + + 75Ω 450Ω 450Ω 450Ω 450Ω – 7 2940Ω – 7 133Ω P 3 3 B B + + 174Ω 75Ω 4 5 4 5 –3.3V –3.3V 6550/51 TAO3 Y = 0.299R + 0.587G + 0.114B PR = 0.713(R – Y) PB = 0.565(B – Y) f3dB ≈ 44MHz 65501fa 14
U TYPICAL APPLICATIO
Consumer products require generation of YPBPR lumi- the desired unity gain is produced for the Y-channel. The nance/chrominance component signals, often from RGB necessary scaling of the color-difference signals is per- source content. The YPBPR format has a luminance signal formed passively by their respective output termination and two weighted color difference signals at baseband. resistor networks. Since this circuit naturally produces Even with their fixed internal gain resistors, two LT6550s bipolar chroma signals (±0.35V at the cable load) regard- connected as shown easily implement the required con- less of RGB offset, the simplest implementation is to version matrix equations. The Y channel is a weighted power the circuit with ±3.3V split supplies. With an avail- average of the 2X amplified RGB signals and with the able output swing of about 5.6V for this supply configura- feedback connection of the Y channel output in the second tion, the circuit handles video with composite syncs and/ LT6550 back to the gain-resistor common pin, an implicit or various offsets without difficulty. Y subtraction is performed for the chroma channels and
RGB to YPBPR Component-Video Conversion
3.3V 3.3V LT6550 10 LT6550 10 450Ω 450Ω 450Ω 450Ω – 9 1070Ω – 9 105Ω 1 P 1 R R + + 261Ω 75Ω 450Ω 450Ω 450Ω 450Ω – 8 549Ω – 8 75Ω Y 2 2 G + + 75Ω 450Ω 450Ω 450Ω 450Ω – 7 2940Ω – 7 133Ω P 3 3 B B + + 174Ω 75Ω 4 5 4 5 –3.3V –3.3V 6550/51 TAO3 Y = 0.299R + 0.587G + 0.114B PR = 0.713(R – Y) PB = 0.565(B – Y) f3dB ≈ 44MHz 65501fa 14