A power supply control IC includes: a switching control circuit of a fixed on-time type configured to generate an output voltage from an input voltage by driving an inductor by complimentarily turning on/off an output transistor and a synchronous rectification transistor based on a result of comparison between a predetermined reference voltage and a feedback voltage in accordance with the output voltage. The switching control circuit extends an on-time of the output transistor more when a backflow of a coil current is detected than when the backflow is not detected.

A switching circuit comprising a transistor (23) and a drive component both for controlling the transistor and also for limiting the power supply current (Ia) suppled to a load (22), the drive component being arranged both to receive a control voltage (V.sub.H) and also: when the control voltage (VH) is disconnection signal, to generate a drive voltage (V.sub.p) that causes the transistor to occupy a non-conductive state; when the control voltage (VH) is a connection signal and the power supply current (Ia) cannot reach a predefined current threshold, to generate drive voltage (V.sub.p) that causes the transistor to occupy saturated conditions; and when the control voltage (VH) is a connection signal and the power supply current (Ia) can reach a predefined current threshold, to generate a drive voltage (V.sub.p) that causes the transistor to occupy linear conditions, such that the power supply current is regulated so that it does not exceed the predefined current threshold.

The present disclosure includes switching regulator circuits and methods. In one embodiment, a first switching regulator stage receives a first input voltage and produces a first voltage on a first node. A second switching regulator stage receives the first input voltage and produces a second voltage on a second node. A capacitor includes a first terminal coupled to the first node and a second terminal coupled to the second node, and the first switching regulator stage and the second switching regulator stage are configured to set a first voltage on the first node and to set a second voltage on the second node.

In a cascode switching device, avalanche breakdown of a control transistor and loss of soft switching or zero voltage switching in a high voltage normally-on depletion mode transistor having a negative switching threshold voltage and the corresponding losses are avoided by providing additional capacitance in parallel with a parallel connection of drain-source parasitic capacitance of the control transistor and gate-source parasitic capacitance of the high voltage, normally-on transistor to form a capacitive voltage divider with the drain-source parasitic capacitance of the high voltage, normally-on transistor such that the avalanche breakdown voltage of the control transistor cannot be reached. The increased capacitance also assures that the drain source parasitic capacitance of the high voltage, normally-on transistor is fully discharged before internal turn-on can occur.

An illumination device described herein includes at least a phosphor converted LED, which is configured for emitting illumination for the illumination device, a first photodetector and a second photodetector. A spectrum of the illumination emitted from the phosphor converted LED comprises a first portion having a first peak emission wavelength and a second portion having a second peak emission wavelength, which differs from the first peak emission wavelength. The first photodetector has a detection range, which is configured for detecting only the first portion of the spectrum emitted by the phosphor converted LED. The second photodetector has a detection range, which is configured for detecting only the second portion of the spectrum emitted by the phosphor converted LED. Methods are provided herein for calibrating and controlling each portion of the phosphor converted LED spectrum, as if the phosphor converted LED were two separate LEDs.

A method for estimating load current in a DC-DC converter, in some embodiments, comprises: identifying a converter capacitor in parallel with a converter load in a DC-DC converter; providing an estimation capacitor based on a capacitance of the converter capacitor; providing said estimation capacitor with an estimation capacitor current based on an inductor current flowing through an inductor in the DC-DC converter; driving an estimation voltage across the estimation capacitor toward a voltage present across the converter capacitor; and using the estimation voltage to generate an estimation current that estimates a load current passing through said converter load.

A multifunctional signal isolation converter (10) is arranged in a safe area (20), and is applied to an electronic apparatus (40) arranged in a dangerous area (30). The multifunctional signal isolation converter (10) includes a microprocessor (108) and a power supply unit (116). The microprocessor (108) determines whether internal functions of the multifunctional signal isolation converter (10) are normal or not to obtain a first judgment value. The electronic apparatus (40) sends an input signal (42) to the microprocessor (108). The microprocessor (108) determines whether functions of the electronic apparatus (40) are normal or not to obtain a second judgment value according to the input signal (42). The microprocessor (108) controls whether the power supply unit (116) supplies a driving power (122) to the electronic apparatus (40) or not according to the first judgment value and the second judgment value.

A multifunctional signal isolation converter (10) is arranged in a safe area (20), and is applied to an electronic apparatus (40) arranged in a dangerous area (30). The multifunctional signal isolation converter (10) includes a microprocessor (108) and a power supply unit (116). The microprocessor (108) determines whether internal functions of the multifunctional signal isolation converter (10) are normal or not to obtain a first judgment value. The electronic apparatus (40) sends an input signal (42) to the microprocessor (108). The microprocessor (108) determines whether functions of the electronic apparatus (40) are normal or not to obtain a second judgment value according to the input signal (42). The microprocessor (108) controls whether the power supply unit (116) supplies a driving power (122) to the electronic apparatus (40) or not according to the first judgment value and the second judgment value.

A solid state light fixture includes a light emitting diode (LED) load and a driver circuit that selectively provides one of a switched-mode drive current and a linear-mode drive current to the LED load in response to a dimming control signal.

There is provided an illumination apparatus including an illumination unit, a reception unit, and a control unit configured to control illumination of the illumination unit in accordance with a default illumination pattern. When the reception unit receives an illumination pattern, the control unit performs illumination control different from the illumination according to the default illumination pattern.