Two-Stage Hysteretic LED Driver with Internal MOSFETs


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The RT8479B is a two-stage controller with dual MOSFETs and consists of a Boost converter (first stage) and a Buck converter (second stage). The advantage of two-stage topology is highly compatible with ET (Electronic Transformer) and extremely high Power Factor performance in MR16 / AR111 lighting market fields applications.

The first stage is a Boost converter for constant voltage output with inductor peak current over-current protection. The second stage is a Buck converter for constant output current by typical constant peak current regulation.

The RT8479B is equipped with dual output gate drivers for internal power MOSFETs.

The RT8479B is available in the SOP-8 (Exposed Pad) package.


  • MR16 Lighting
  • Signage and Decorative LED Lighting
  • Architectural Lighting
  • High Power LED Lighting
  • Low Voltage Industrial Lighting
  • Indicator and Emergency Lighting
  • Automotive LED Lighting
Key Spec.
Status NRND
Recommended Alternative  RT8479C
Vin (min) (V) 4.5
Vin (max) (V) 36
Vout (max) (V) 36
LED Channels 1
SW Freq (typ) (kHz) 600
Vcs (typ) (mV) 130
Features OCP;OVP
Package Type PSOP-8
  • Two-Stage Topology (Boost + Buck)
  • Dual MOSFETs Inside
  • Wide Input Voltage Range : 4.5V to 36V
  • Excellent Power Factor
  • Programmable Boost Output Voltage
  • Independent Dual Stage Function
  • Programmable LED current with ±5% LED Current Accuracy
  • Input Under-Voltage Lockout Detection
  • Thermal Shutdown Protection
Technical Documents
TitleLast UpdateShareDownload
Minimizing Light Flicker in LED Lighting Applications2018/08/15