The BA7230LS comprises an RGB signal matrix circuit, balanced modulator circuit (rectangular 2-phase modulation), oscillator circuit (VCXO) for a 3.58MHz subcarrier synchronized with video input burst signals, luminosity and color difference signal mixing circuit, and a high speed switch for selecting composite signals of video input and RGB input. RGB signals, synch signals, BFP (burst flag pulses), PCP (pedestal clamp pulses) are input, and an NTSC composite signal is output.