This third-generation Primary-Side-Regulation (PSR) and highly integrated PWM controller provides features to enhance the performance of LED illumination. The proprietary topology, TRUECURRENT®, enables precise CC regulation and simplified circuit for LED illumination applications. The result is lower-cost and smaller LED lighting compared to a conventional design or a linear transformer. To minimize standby power consumption, the proprietary green-mode function provides off-time modulation to linearly decrease PWM frequency with cycle skipping under light-load conditions. Green mode assists the power supply in meeting the power conservation requirements. By using the FL663, LED illumination can be implemented with few external components and minimized cost.