The video and audio channels feature input source selection multiplexers, input buffers, and output buffers for routing all inputs to selected outputs. The MAX4397D audio encoder input is differential DC-coupled, while the MAX4397S audio encoder input is single-ended ACcoupled. Except for the MAX4397D's audio encoder input, all other inputs and outputs are AC-coupled with internal DC-biasing set to predefined levels. The MAX4397 provides programmable gain control from +5dB to +7dB in 1dB steps for Red, Green, and Blue component video signals. All other video outputs have a fixed +6dB gain. Additional features include an internal Luma and Chroma (Y/C) mixer that generates a Composite video signal (CVBS) to supply an RF modulator output, and internal video reconstruction lowpass filters with a cutoff frequency of 6MHz. The MAX4397 TV audio channel features clickless switching and programmable volume control from -56dB to +6dB in 2dB steps. The VCR audio output also has programmable gain for -6dB, 0dB, or +6dB. The device also generates monaural audio from left and right stereo inputs. All audio drivers deliver a 3.0VRMS minimum output. The MAX4397 operates with standard 5V and 12V power supplies and supports slow-switching and fastswitching signals. The I 2 C interface programs the gain and volume control, and selects the input source for routing.