High efficiency LED driving circuit and driving method

摘要

In one embodiment, an LED driving circuit can include: (i) a sense circuit configured to sense an inductor voltage, and to generate a sense voltage signal; (ii) a protection control circuit configured to activate a first protection control signal in response to a comparison of the sense voltage signal against a first reference voltage to indicate an LED device is in a first load state; (iii) the protection control circuit being configured to activate a second protection control signal in response to a comparison of the sense voltage signal against a second reference voltage to indicate the LED device is in a second load state; and (iv) a PWM control circuit configured to control a power switch according to the first protection control signal or the second protection control signal, based on the load state of the LED device.

主权项

1. A light-emitting diode (LED) driving circuit, comprising:
a) a sense circuit configured to sense a voltage of an inductor, and to generate a sense voltage signal therefrom; b) a protection control circuit configured to activate a first protection control signal in response to a comparison of said sense voltage signal against a first reference voltage to indicate an LED device is in a first load state; c) said protection control circuit being configured to activate a second protection control signal in response to a comparison of said sense voltage signal against a second reference voltage to indicate said LED device is in a second load state; and d) a pulse-width modulation (PWM) control circuit configured to control a power switch according to said first protection control signal when said LED device is in said first load state, and to control said power switch according to said second protection control signal when said LED device is in said second load state.