ON Semiconductor – LED controller achieves highly stable current regulation


ON Semiconductor’s FL7733A is a highly integrated LED controller which implements a single-stage Primary- Side Regulation (PSR) technique to enhance the performance of the power circuit driving low or mid-power LEDs.

Driver circuits based on the FL7733A require few external components. The LED current is accurately controlled by ON Semiconductor’s innovative PSR technology, backed by excellent feedback loop control. Constant Current (CC) tolerance is less than ±1% over the universal line voltage range, enabling
LED lighting systems to maintain consistent brightness.

In addition, the FL7733A minimises fluctuation in turn-on time and has a high power factor. As a result, it achieves total harmonic distortion of less than 10% over the universal line voltage range.

An integrated high-voltage start-up circuit implements fast start-up and high system efficiency.

During start-up, the adaptive feedback loop control anticipates the steady-state condition and sets the initial feedback condition close to the steady state, to ensure that it does not overshoot or undershoot the LED current.

ON Semiconductor also supplies a related part, the FL7734 PSR LED controller which includes phase-cut dimming capability. The active dimmer-control technology in the FL7734 achieves smooth performance and excellent dimmer compatibility without visible flicker, even at low power levels and high input voltages.


  • >0.9 power factor
  • Very wide output-voltage range
  • Power-rating range: 5W to 60W
  • LED short protection
  • LED open protection
  • Output diode short protection
  • Over-temperature protection


  • A19 bulbs
  • PAR30/38 bulbs
  • Downlights
  • Flat lights
  • Exterior lighting

Orderable Part Number: FEBFL7733A_L53U021A