A2624 is a 3D 3-key crystal-free 2.5x resolution enhancement optical mouse controller designed for USB and PS/2 applications. It minimizes external components to ensure competitive low BOM cost. A2624 supports the USB Standard v1.1 as well as HID Class Definition v1.1. It is compatible with Microsoft 3D Intellimouse and IBM PS/2 mouse. It also supports mechanical and opto-mechanical scrolling.