The TPS92074 is a hybrid power factor controller (PFC) optimized for drivingLED lighting solutions. The device monitors the converter rectified AC waveformusing an internal, low-power, digital controller. The controller and DACgenerate a synchronized triangular reference to regulate the output current. Byallowing for some variation in the LED current over a line cycle and maintaininga regulated overall average current, high power factor solutions can beachieved.
Using a constant off-time control, the solution achieves low component count,high efficiency and inherently provides variation in the switching frequency.This variation creates an emulated spread spectrum effect easing the convertersEMI signature and allowing a smaller input filter.
The TPS92074 also includes standard features: current limit, overvoltageprotection, thermal shut-down, and VCC undervoltage lockout, all in packages