Abstract: A power supply device and an operation method thereof are provided. The power supply device includes a charge pump circuit and a power supply circuit. The power supply circuit supplies a first power voltage to the charge pump circuit. The charge pump circuit converts the first power voltage into a second power voltage so as to supply the second power voltage to an application circuit. The power supply circuit detects the second power voltage or an output current output by the charge pump circuit to obtain a detection result. The power supply circuit dynamically adjusts the first power voltage based on the detection result.

Abstract: An Alternating-current-Direct-current (AC-DC dual-use) Light Emitting Diode (LED) driving circuit includes an input power circuit, a buck-boost converter, and a Pulse Width Modulation (PWM) signal controller. The buck-boost converter, including a switching transistor and a feedback resistor, receives a current signal output from the input power circuit, and drives an LED with a driving signal. The PWM signal controller outputs a PWM signal according to the driving signal, so as to sequentially turn on and turn off the switching transistor. One end of the feedback resistor is coupled to the LED, and a floating ground terminal of the PWM signal controller is coupled to the switching transistor and the other end of the feedback resistor. Therefore, the AC-DC dual-use LED driving circuit is capable of dynamically adjusting the duty ratio of the PWM signal without connecting an external photocoupler.

Abstract: An Alternating-current-Direct-current (AC-DC dual-use) Light Emitting Diode (LED) driving circuit includes an input power circuit, a buck-boost converter, and a Pulse Width Modulation (PWM) signal controller. The buck-boost converter, including a switching transistor and a feedback resistor, receives a current signal output from the input power circuit, and drives an LED with a driving signal. The PWM signal controller outputs a PWM signal according to the driving signal, so as to sequentially turn on and turn off the switching transistor. One end of the feedback resistor is coupled to the LED, and a floating ground terminal of the PWM signal controller is coupled to the switching transistor and the other end of the feedback resistor. Therefore, the AC-DC dual-use LED driving circuit is capable of dynamically adjusting the duty ratio of the PWM signal without connecting an external photocoupler.