LD7841KSingle-Stage, High Power Factor, Constant Voltage Output Controller Primary-Side Regulation with Integrated High Voltage Startup
The LD7841K is a voltage mode controller for constant voltage output to LED drivers. Designed to support flyback or buck-boost topologies, its proprietary voltage mode control algorithm provides near−unity power factor and tightly regulates a constant output voltage from the primary side, thus eliminating the need for a secondary side feedback circuitry or an opticalcoupler.
The device is highly integrated with a minimum number of external components. A robust suite of safety protection is built in to simplify the design. This device is specifically intended for very compact space efficient designs and also provides a constant voltage regulation of the output if no load is connected to the LED drivers.
Features
- Wide universal input range (85VAC ~ 305 VAC)
- Fast Startup time: ≦ 0.5 sec
- Low standby power
- No load power saving : < 0.3W
- Standby power consumption: < 0.5W - Precise voltage regulation in the steady state : < ± 3 %
- Voltage regulation in the load transient: < ± 15%
- Total harmonic distortion current (THDi) optimization: <10%
- High Power Factor : PF > 0.9
- Robust Protection Features
- Brown−In/Out Detection on HV pin
- Cycle−by−cycle Peak Current Limit on CS pin
- Over Load Protection on COMP pin
- Secondary Diode short Protection on CS pin
- Pin Short/Open Circuit Protection on CS and FB pin
- Output Short Circuit Protection on FB pin
- External OTP on CS pin
- Internal Over Temperature Protection
- 250 mA / -700 mA Totem Pole Driving capability
Applications
- LED Driver Power Supplies
- Offline Appliances Requiring Power Factor Correction
