The iW3637 high-voltage, second-stage buck LED driver provides constant current to LEDs directly from DC power supplies. It supports non-isolated buck and flyback converter topologies to post-regulate from a PFC AC/DC boost 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.


  • Single-Stage DC/DC Buck or Flyback Topology
  • Supports Wide DC Input Voltage with Tight Output Current Regulation (±3%)
  • Output Power up to 150W
  • PrimAccurate™ Primary-Side Control for Excellent Output Current Regulation with No Direct Voltage and Current Feedback Components Needed
  • Independent Maximum Load Current Setting Interface
  • PWM Dimming
  • Wide Dimming Range: 1% - 100%, with 1% Resolution
  • Configurable Minimum Dimming Setting
    • Dim-to-Off, 1%, 5% or 10%
  • Fully Protected
    • Output Overvoltage, Output Open, Output Short, Overcurrent, Peak Current Limit, Sense-Resistor Short Protections
    • Input Voltage Undervoltage Protection
    • Built-In Over-Temperature Protection or External NTC
    • Brown-In and Brown-Out Protection
  • Small SOIC 8-Lead Package




  • Commercial Lighting:
    • T8
    • 0-10V Dimming
    • External Fixture Drivers
    • Wireless and Intelligent LED Lighting Systems

Design & Development