Fully Differential 4-th Order Active Lowpass Filter for AHD-H and Full-HD Video Transmitting Systems in 65 nm CMOS

Currently, wireless video signal transmission systems are becoming more widespread, while the requirements for image quality and transmission distance are increasing. AHD-H and FULL HD video signal widths reach 25 ... 28 MHz, while components of higher frequencies that may appear in the spectrum under the influence of external conditions must be filtered out before applying signal to the modulator. The article describes a fully differential fourth-order active low-pass filter constructed using two operational amplifiers. The upper cutoff frequency has tuning in the range of 25 ... 40 MHz; the maximum output signal amplitude is rail-to-rail, with a total harmonic distortion of not more than 0.8%. Active filter developed in 65 nm process, current consumption is not more than 30 mA.