What this part is — a 6-bit color palette RAM-DAC for video display systems
The Analog Devices ADV476KN40 is a 6-bit, 3-channel color palette RAM-DAC designed for video graphics applications, such as VGA and EGA display subsystems. It integrates three 6-bit D/A converters with a 256 × 18 color lookup table, allowing simultaneous red, green, and blue analog output from a digital pixel stream. The part operates from a single 4.5 V to 5.5 V supply for both analog and digital rails, and is specified over the commercial temperature range of 0°C to 70°C.
Package and mounting — through-hole legacy, still serviceable
Housed in a 28-pin PDIP (0.600" body width, 15.24 mm row spacing), the ADV476KN40 is a through-hole part. That footprint suits prototype boards, socketed designs, or retrofit into older video cards where a surface-mount rework is impractical.
The product status is Active. For dual-sourcing or a surface-mount alternative, the PLCC package variant is the same die in a different package, though the evidence does not list it as a formal second source.