Patent ID: 8890425

Claim:
A blend dimming method for driving a light load, the method comprising: a) converting an external sinusoidal AC power supply to a phase-missing DC voltage signal; b) detecting a conduction angle of said phase-missing DC voltage signal to generate a first control signal that represents said conduction angle; c) generating an analog dimming signal based on said first control signal; d) generating, by a pulse-width modulation (PWM) dimming circuit, a PWM dimming signal based on said analog dimming signal and an output feedback signal of said light load; e) regulating a brightness of said light load by PWM dimming when said conduction angle is greater than a threshold angle; f) regulating said brightness of said light load by said PWM dimming and analog dimming when said conduction angle is less than said threshold angle; and g) enabling said PWM dimming circuit to control a power stage circuit to regulate said brightness of said light load when said first control signal is active.