Fig. 1. Comparison of pulse waveforms under PDM and PWM method

Fig. 2. Logic block diagram of PDM modulation method

Fig. 3. Response time of dimming circuit

Fig. 4. Input and output curves of the two modulation methods

Fig. 5. Logic block diagram with control precision adjustment

Fig. 6. Periodic rectangular pulse signal spectrum

Fig. 7. Signal spectrum of the two modulation methods

Fig. 8. Equivalent circuit model and simulation model of LCR

Fig. 9. Simulation waveforms of the two methods

Fig. 10. CE101 test results of the two methods

Fig. 11. CE102 test results of the two methods

Fig. 12. RE102 test results of the two methods

Fig. 13. Measured current waveforms of the two methods