• Primary side control eliminates the Opto-coupler
• 0~10V Dimming Range from 5% to100%
• Integrated Dimming Transformer Driver enables isolation between the LED driver and the dimming controller
• Compatible with Leading/Trailing Edge Dimmer
• Primary MOSFET Valley Turn-on reduces switching losses
• Integrated High Voltage Start-up Function Start-up Time<300ms
• Low Standby Power<500mW
• Reliable Short LED and Open LED Protections
• Power Factor >0.90
• Internal High Current MOSFET Driver: ▪ 0.19A Sourcing and 0.6A Sinking
• Compact Package: SO8 

The SY5989 is a single stage Flyback and PFC controller used to drive LEDs in isolated dimming applications. Using a voltage generated by an external dimming controller, the LEDs can be dimmed between 5% and 100% (fully ON). The primary side constant current control architecture doesn’t require secondary feedback circuit, and enables reducing the overall system cost, while the quasi-resonant mode of operation is used to achieve high efficiency. The device uses a Constant on Time (COT) control to achieve a high-power factor. It integrates a transformer driver to simplify the design and enable the use of an isolation barrier between a 0~10V dimming controller and the LED string.