| 摘要 |
PROBLEM TO BE SOLVED: To provide an LED drive circuit that achieves stable current output, overcurrent protection, overvoltage protection, and power-factor correction.SOLUTION: A light-emitting diode (LED) drive circuit includes a power-factor correction (PFC) circuit 120 and a drive controller 130. The PFC circuit controls the power-factor of the LED drive circuit. The LED drive circuit includes an inductor, a switch, a current detection circuit, and a time detection circuit. The inductor detects an inductor current and supplies energy to at least one LED. The switch connected to the inductor is conductive according to a driving signal. The current detection circuit connected to the switch detects inductor current information. The time detection circuit connected to the switch detects the energy emission time while the inductor current reduces from the peak value to zero. The drive controller connected to the switch, the current detection circuit, and the time detection circuit outputs the driving signal to the switch according to a voltage level and the energy emission time. |
