Abstract: The present application provides method and circuit for monitoring a voltage of a power supply, which adopts a divided voltage circuit to obtain a divided voltage from an input voltage of an input power source generated from the power supply, for detecting the input voltage according to the divided voltage by adopting a first detection circuit and a second detection circuit. Also, judging whether the divided voltage is clamped according to a clamp threshold value to determine the first detection circuit or the second detection circuit detecting a detection current and determine another detection circuit detecting the divided voltage. Hereby, the input voltage transmitted from a rectification circuit to the power supply is monitored, and the dependence between the two detection circuits is avoided.

Abstract: A switch control module for a switch mode power supply comprising a biased switch, an active switch and a control unit. The biased switch comprises a first node and a second node. The first node is coupled to a primary side winding. The active switch is connected to the second node. The control unit controls the ON/OFF states of the active switch and the biased switch is biased to be turned on initially. In this way, the active switch and the control unit are less likely to be damaged by voltage spikes generated by leakage in the primary side winding.

Abstract: The present application discloses a reference voltage circuit with temperature compensation, in which a voltage with a positive temperature coefficient is provided by a current source and an impedance device, and in the meanwhile, a voltage with a negative temperature coefficient is provided by a voltage source. Hereby, the reference voltage circuit according to the invention provides a reference voltage with temperature compensation at an output terminal.

Abstract: The present application provides a synchronous rectification circuit and a control method thereof. A switching element of the synchronous rectification circuit is controlled to turn on or turn off by detecting the occurrence of a positive or negative transition of the inductive voltage of the secondary winding. The synchronous rectification circuit comprises a transition detector for coupling to the secondary winding, a transition controller for coupling to the transition detector, and a switching element comprising a control terminal for coupling to the transition controller.

Abstract: The present application provides a synchronous rectification circuit, which adopts a multiplexer that selectively inputs a first reference signal or a second reference signal to a comparator by coupling the first and second reference signal. A comparing signal is generated to a switch element by comparing a switch input signal. Hereby, the switch element is under control for synchronous rectification.

Abstract: The present application provides method and circuit for monitoring a power supply, which firstly obtains an auxiliary side voltage from a switching power supply and then adopts a divided voltage circuit to obtain a divided voltage from the auxiliary side voltage, for detecting the divided voltage and a detected current flowed in the detection circuit with adopting a first detection circuit and a second detection circuit in an switch circuit to correspondingly generate a first and a second detection signals, which is corresponding to an ambient temperature and an output voltage of the power supply. Hereby, the power supply is monitored.

Abstract: The present application provides method and circuit for monitoring a voltage of a power supply, which adopts a divided voltage circuit to obtain a divided voltage from an input voltage of an input power source generated from the power supply, for detecting the input voltage according to the divided voltage by adopting a first detection circuit and a second detection circuit. Also, judging whether the divided voltage is clamped according to a clamp threshold value to determine the first detection circuit or the second detection circuit detecting a detection current and determine another detection circuit detecting the divided voltage. Hereby, the input voltage transmitted from a rectification circuit to the power supply is monitored, and the dependence between the two detection circuits is avoided.

Abstract: The present invention is a switching circuit driving method for power converters and its driving module. Such driving method and driving module can avoid the occurrence of valley jumping by replacing the original blanking time with a front blanking time or a back blanking time when a valley jumping occurs in the system, and avoid the noise problem caused by valley jumping.

Abstract: An over-current protection module for a flyback power supply having a transformer includes: a switch control unit, configured to generate a control signal in a first period to control a transistor switch coupled to a primary side of the transformer, wherein the transistor switch is turned on in a first duty cycle of the control signal and the transistor switch is turned off in a second duty cycle of the control signal; a transformation unit, configured to generate a compensation current according to the second duty cycle; a timing control unit, configured to output the compensation current to an impedance unit to generate an impedance cross voltage in a shut-off period of the transistor switch of the first period; and a current control unit, configured to determine an over-current reference voltage according to the impedance cross voltage for the over-current protection module in a second period following the first period.

Abstract: An over-current protection module for a flyback power supply having a transformer includes: a switch control unit, configured to generate a control signal in a first period to control a transistor switch coupled to a primary side of the transformer, wherein the transistor switch is turned on in a first duty cycle of the control signal and the transistor switch is turned off in a second duty cycle of the control signal; a transformation unit, configured to generate a compensation current according to the second duty cycle; a timing control unit, configured to output the compensation current to an impedance unit to generate an impedance cross voltage in a shut-off period of the transistor switch of the first period; and a current control unit, configured to determine an over-current reference voltage according to the impedance cross voltage for the over-current protection module in a second period following the first period.

Abstract: A control module for a flyback power converting device is coupled between a primary side winding of the flyback power converting device and a power end and includes a switch unit coupled to the primary side winding; wherein the control module conducts a connection between the primary side winding and the power end when the switch unit is disconnected; wherein the power end is able to provide an operation current to the control module.

Abstract: A control module for a flyback power converting device is coupled between a primary side winding of the flyback power converting device and a power end and includes a switch unit coupled to the primary side winding; wherein the control module conducts a connection between the primary side winding and the power end when the switch unit is disconnected; wherein the power end is able to provide an operation current to the control module.