Diodes Inc AP1688 LED buck controller is a high performance factor, constant current buck controller for universal LED driver applications. The AP1688 operates under Boundary Conduction Mode (BCM) to achieve high efficiency, low electromagnetic interference (EMI) and low total harmonic distortion (THD). The AP1688 uses open loop control to deliver excellent line and load regulation. It also features fast start-up, low start-up current and low operation current. Comprehensive protection features include under-voltage lockout (UVLO), over-voltage protection (OVP), over-current protection (OCP), over-temperature protection (OTP) and LED short and open protection.