Abstract: A power supplying circuit includes a first high-voltage switch, a first low-voltage switch, a second high-voltage switch, a second low-voltage switch, and a controller circuit. The first high-voltage switch receives a first input voltage and generates a first node voltage. The first low-voltage switch is coupled between the first high-voltage switch and an output terminal. The second high-voltage switch receives a second input voltage and generates a second node voltage. The second low-voltage switch is coupled between the second high-voltage switch and the output terminal. The controller circuit controls the first high-voltage switch, the first low-voltage switch, the second high-voltage switch, and the second low-voltage switch according to the first node voltage and the second node voltage such that an output voltage is outputted to the output terminal.

Abstract: A bidirectional signal conversion circuit is configured to perform a signal conversion between a first port and a second port, and includes a switch, a first pull-up resistor, a second pull-up resistor, a first output-response enhancement circuit, and a second output-response enhancement circuit. The switch is coupled between the first port and the second port, and operates according to a bias. The first (second) pull-up resistor is coupled between the first (second) port and a high (low) voltage terminal having a high (low) voltage. The first (second) output-response enhancement circuit includes a first (second) alternative-current (AC) coupling circuit and a first (second) output-stage circuit. When the first (second) port and the second (first) port functions as an input port and an output port respectively, the first (second) output-response enhancement circuit is operable to accelerate the transient response of the output port.

Abstract: A power supplying circuit includes a first high-voltage switch, a first low-voltage switch, a second high-voltage switch, a second low-voltage switch, and a controller circuit. The first high-voltage switch receives a first input voltage and generates a first node voltage. The first low-voltage switch is coupled between the first high-voltage switch and an output terminal. The second high-voltage switch receives a second input voltage and generates a second node voltage. The second low-voltage switch is coupled between the second high-voltage switch and the output terminal. The controller circuit controls the first high-voltage switch, the first low-voltage switch, the second high-voltage switch, and the second low-voltage switch according to the first node voltage and the second node voltage such that an output voltage is outputted to the output terminal.

Abstract: The present invention provides an interface circuit, wherein the interface circuit includes a switching circuit, an over-voltage detection circuit and a control signal generating circuit. In the operations of the interface circuit, the switching circuit is configured to receive an input signal from an input terminal, and selectively transmit the input signal to an internal circuit. The over-voltage detection circuit is configured to detect whether a voltage level of the input signal is greater than a threshold value, and accordingly generate at least one over-voltage signal. The control signal generating circuit is configured to generate a control signal according to said at least one over-voltage signal, to control the switching circuit to be in one of three or more states.

Abstract: The present invention provides an interface circuit, wherein the interface circuit includes a switching circuit, an over-voltage detection circuit and a control signal generating circuit. In the operations of the interface circuit, the switching circuit is configured to receive an input signal from an input terminal, and selectively transmit the input signal to an internal circuit. The over-voltage detection circuit is configured to detect whether a voltage level of the input signal is greater than a threshold value, and accordingly generate at least one over-voltage signal. The control signal generating circuit is configured to generate a control signal according to said at least one over-voltage signal, to control the switching circuit to be in one of three or more states.

Abstract: An AC-to-DC power converter with a BJT as a power switch can set a base current of the BJT by a current setting resistor which is in the outside of a control integrated circuit. Since an output current and a recovery current of the BJT are injected into a sensing resistor, the AC-to-DC power converter can correctly detect an inductor current thereof from the sensing resistor.

Abstract: A mixed mode compensation circuit for a power converter generate a digital signal according to a reference signal and a feedback signal which is related to the output voltage of the power converter, convert the digital signal into a first analog signal, offset the first analog signal with a variable offset value to generate a second analog signal, and filter out high-frequency components of the second analog signal to generate a third analog signal for stable output voltage of the power converter. The mixed mode compensation does not require large capacitors, and thus the circuit can be integrated into an integrated circuit.

Abstract: A mixed mode compensation circuit for a power converter generate a digital signal according to a reference signal and a feedback signal which is related to the output voltage of the power converter, convert the digital signal into a first analog signal, offset the first analog signal with a variable offset value to generate a second analog signal, and filter out high-frequency components of the second analog signal to generate a third analog signal for stable output voltage of the power converter. The mixed mode compensation does not require large capacitors, and thus the circuit can be integrated into an integrated circuit.

Abstract: A light emitting device circuit has one or plural light emitting devices connected in series. A light emitting device driver circuit drives the light emitting device circuit according to a rectified input voltage. The light emitting device driver circuit includes a power switch and a control circuit. When the power switch is conductive, a light emitting device current flows through the light emitting device circuit and the power switch. When the power switch is not conductive, an output capacitor discharges to provide the light emitting device current. The control circuit determines whether the rectified input voltage is lower or not lower than a forward voltage plus a reference voltage according to a voltage at a reverse end of the light emitting device circuit, and control the power switch accordingly.

Abstract: A linear LED driver comprises a transistor having an input terminal coupled to a LED. When the transistor is turned on, the LED is lighted. The linear LED driver further includes a protection circuit for judging whether an instant high voltage variation occurs or not according to at least one of the voltages of a control terminal and an output terminal of the transistor so as to achieve a protection function.

Abstract: A mixed mode compensation circuit for a power converter generate a digital signal according to a reference signal and a feedback signal which is related to the output voltage of the power converter, convert the digital signal into a first analog signal, offset the first analog signal with a variable offset value to generate a second analog signal, and filter out high-frequency components of the second analog signal to generate a third analog signal for stable output voltage of the power converter. The mixed mode compensation does not require large capacitors, and thus the circuit can be integrated into an integrated circuit.

Abstract: A frequency jittering control circuit for a PFM power supply includes a pulse frequency modulator to generate a frequency jittering control signal to switch a power switch to generate an output voltage. The frequency jittering control circuit jitters an input signal or an on-time or off-time of the pulse frequency modulator to jitter the switching frequency of the power switch to thereby improve EMI issue.

Abstract: A driver circuit of a LED luminance device includes: a signal pin; a determining circuit for determining the magnitude of an input signal; an indication signal generating circuit for outputting an indication signal to the signal pin according to the determining result of the determining circuit; an alignment signal generating circuit for generating an alignment signal when triggered by a predetermined edge of a signal at the signal pin; an indication signal detecting circuit for detecting the signal at the signal pin to generate a detection signal; and a control signal generating circuit for generating multiple control signals according to the detection signal to respectively control multiple switching elements in parallel connection with multiple LED devices when triggered by the alignment signal.

Abstract: A mixed mode compensation circuit for a power converter generate a digital signal according to a reference signal and a feedback signal which is related to the output voltage of the power converter, convert the digital signal into a first analog signal, offset the first analog signal with a variable offset value to generate a second analog signal, and filter out high-frequency components of the second analog signal to generate a third analog signal for stable output voltage of the power converter. The mixed mode compensation does not require large capacitors, and thus the circuit can be integrated into an integrated circuit.

Abstract: A mixed mode compensation circuit for a power converter generate a digital signal according to a reference signal and a feedback signal which is related to the output voltage of the power converter, convert the digital signal into a first analog signal, offset the first analog signal with a variable offset value to generate a second analog signal, and filter out high-frequency components of the second analog signal to generate a third analog signal for stable output voltage of the power converter. The mixed mode compensation does not require large capacitors, and thus the circuit can be integrated into an integrated circuit.

Abstract: A mixed mode compensation circuit for a power converter generate a digital signal according to a reference signal and a feedback signal which is related to the output voltage of the power converter, convert the digital signal into a first analog signal, offset the first analog signal with a variable offset value to generate a second analog signal, and filter out high-frequency components of the second analog signal to generate a third analog signal for stable output voltage of the power converter. The mixed mode compensation does not require large capacitors, and thus the circuit can be integrated into an integrated circuit.

Abstract: A frequency jittering control circuit for a PFM power supply includes a pulse frequency modulator to generate a frequency jittering control signal to switch a power switch to generate an output voltage. The frequency jittering control circuit jitters an input signal or an on-time or off-time of the pulse frequency modulator to jitter the switching frequency of the power switch to thereby improve EMI issue.

Abstract: An AC-to-DC power converter with a BJT as a power switch can set a base current of the BJT by a current setting resistor which is in the outside of a control integrated circuit. Since an output current and a recovery current of the BJT are injected into a sensing resistor, the AC-to-DC power converter can correctly detect an inductor current thereof from the sensing resistor.

Abstract: A linear LED driver includes a voltage supply terminal providing a driving voltage, at least one first transistor, each of which has an input terminal coupled to a respective LED, and a bleeder circuit. When the voltage of the output terminal of each of the at least one first transistor is lower than a first threshold and a power voltage is higher than a second threshold, the bleeder circuit will generate a bleeder current to discharge the voltage supply terminal so as to prevent the LEDs from flickering. The bleeder circuit detects the voltage of the output terminal of each of the at least one first transistor. Therefore, whether the LEDs are lighted up can be confirmed so that the bleeder current can be provided at properly time point.

Abstract: An apparatus and a method for implementing a multiple function pin in a boundary conduction mode power supply, uses a same pin to switch a power switch and to achieve zero current detection to reduce pin count and save cost of a control integrated circuit. A first voltage is applied to the multiple function pin to turn on the power switch, and then a second voltage is applied to the multiple function pin after the power switch has been turned on for a first time, to thereby turn off the power switch. After the power switch has been turned off for a second time, a third voltage is applied to the multiple function pin keep the power switch off. Preferably, a tristate output driver is used to provide the first and second voltages, and a clamping circuit is used to provide the third voltage.