The iW3638 second-stage buck LED driver provides constant current to LEDs directly from DC power supplies. It supports a non-isolated buck converter topology to post-regulate from an off-line AC/DC converter, minimizing low frequency output ripple current and eliminating virtually all flicker in the system, even down to 1%. A wide range of DC input voltages simplifies design by enabling the use of just one second-stage driver across any commercial lighting product portfolio.