Low-cost video decoder with 2D2L comb filter for NTSC digital TVs

A low-cost video decoder for NTSC signals is described in this paper. The proposed NTSC video decoder design employs a 2D2L comb filter, and a DDFS (direct digital frequency synthesizer)-based DCO (digital control oscillator) based on a trigonometric quadruple angle formula in a digital PLL to track and lock the demodulation clocks. The complexity of the digital video decoder is consequently drastically reduced. The overall cost of the proposed design is 7.22 mm² (26 K gates). The maximum power dissipation is 109.2 mW at the highest clock rate which is 21.48 MHz.