The MAX7438/MAX7439 are three-channel standard definition video reconstruction filters that include a back-porch clamp that sets the output blanking level of the video signal to ground. Each channel combines a lowpass filter with adjustable high-frequency boost levels and an output buffer capable of driving two standard 150Ω video loads. The blanking level of the output video signal on each channel is clamped to ground, eliminating the need for large AC-coupling output capacitors. Direct input coupling circuitry eliminates the need for AC-coupling input capacitors. This DC-in/DC-out architecture results in extremely low line-time distortion. The MAX7438/MAX7439 are ideal for antialiasing and DAC smoothing in digital video devices such as STBs, DVDs, PVRs, and hard disk recorders. The MAX7438/MAX7439 operate from ±5V dual supplies. The three-channel MAX7438/MAX7439 are ideal for Y, Pb, Pr, and RGB component video signals, three composite video signals, and also Y/C plus CVBS video signals.
The MAX7438 and MAX7439 are three‑channel standard video reconstruction filters that include a back‑porch clamp to ground, eliminating the need for large AC‑coupling capacitors. Each channel combines a low‑pass filter with adjustable high‑frequency boost and an output buffer capable of driving two standard 150 Ω video loads.
The datasheet provides absolute maximum ratings, electrical characteristics, typical operating characteristics, pin descriptions, external resistor values for boost and bypass modes, and layout recommendations for power‑supply bypassing. Package information for the 20‑pin 5 mm × 5 mm Thin QFN is also included.
| Number of channels | 3 |
|---|---|
| Back‑porch clamp | Output blanking level clamped to ground |
| Passband attenuation at 27 MHz | 60 dB |
| Passband ripple | +0.8 dB up to 5 MHz |
| Supply voltage | Dual +5 V |
| Package type | 20‑pin 5 mm × 5 mm Thin QFN |
The devices operate from dual +5 V supplies.
The stopband provides at least 55 dB attenuation at 27 MHz.