FMS6410B: Dual-Channel Video Drivers with Integrated Filters and Composite Video Summer

The FMS6410B is a dual Y/C fifth-order Butterworth low-pass video filter optimized for minimum overshoot and flat group delay. The device also contains a summing circuit to generate filtered composite video. In a typical application, the Y and C input signals from DACs are AC coupled into the filters. Both channels have DC restore circuitry to clamp the DC input levels during video sync. The Y and C channels use separate feedback clamps. The clamp pulse is derived from the Y channel.

All outputs are capable of driving 2VPP, AC or DC coupled, into either a single or dual video load. A single video load consists of a series 75Ω impedance matching resistor connected to a terminated 75Ω line. This presents a total of 150Ω of loading to the part. A dual load is two of these in parallel, which presents a total of 75Ω to the part. The gain of the Y, C, and CV signals is 6dB with 1VPP input levels. All video channels are clamped during sync to establish the appropriate output voltage reference levels.

Features

• 7.1MHz fifth-order Y, C filters with composite summer
• 50dB stopband attenuation at 27MHz on Y, C, and CV outputs
• Better than 0.1dB flatness to 4.5MHz on Y,C, and CV outputs
• No external frequency selection components or clocks
• <5ns group delay deviation on Y, C, and CV outputs
• AC-coupled inputs
• AC-or DC-coupled outputs
• Capable of PAL frequency selection components or clocks
• 0.3% differential gain with 0.2° differential phase on Y,C, and CV channels
• Integrated DC restore circuitry with low tilt
• Lead-free SOIC-8 package

Application Notes