The HT16C21 SOP24 is a LCD driver chip manufactured by Holtek. It is a surface mounted device (SMD) in a Small Outline Package (SOP24) measuring 300mil. It is compliant with RoHS (Restriction of Hazardous Substances) guidelines for hazardous material content. The chip is designed to provide an interface between LCD displays and a microcontroller. It includes a programmable 8 segment character generator, a static RAM memory and a 16-bit receive/transmit shift register. It also has 8 segment drivers for controlling the LCD display and 4 common drivers for multiplexing. The chip is suitable for multiple applications such as industrial controllers, factory automation, temperature controllers, etc.