Abstract: A DC brushless motor system is disclosed. When a rotor of the DC brushless motor is close to an aligned position, there will be current spike in the coil and voltage spike in an input capacitor. By decreasing the peak current limit of the current in the coil when the rotor is close to the aligned position, the current spike and the voltage spike are reduced.

Abstract: The present invention discloses a step up circuit with output floating for driving a load such as a LED or a series of LEDs in a string. The step up circuit comprises an input port, an output port, an inductor, an input capacitor, an output capacitor, a first switch, a second switch and a third switch. The third switch S3 is an additional switch for purpose of high dimming ratio control, short circuit protection and input disconnection realization. Further, the third switch can implement an additional LDO function when the voltage at the input port is larger than the voltage across the load.

Abstract: The present technology discloses a switching mode power supply with predicted PWM control. In one embodiment, the switching mode power supply monitors the slew rate of COMP signal which represents the output voltage of the switching mode power supply. When the load steps up, the ON state of the power stage is prolonged; when the load steps down, the power stage is turned off earlier.

Abstract: Embodiments of circuits and methods for a switching mode power supply are described in detail herein. In one embodiment, a switching mode power supply includes a transformer having a primary winding and a secondary winding to supply power to a load, a feedback circuit that generates a feedback signal that varies in relation to the load on the secondary winding, a switching circuit coupled to the primary winding to control current flow through the primary winding, and a control circuit coupled to the switching circuit to control the on/off status of switching circuit in response to the feedback signal and the current flow through the primary winding. The control circuit comprises a spectrum shaping circuit configured to generate a spectrum shaping signal in response to the feedback signal. The spectrum shaping signal can then be used to regulate the switching frequency and the spectrum shaping range.

Abstract: A zero-crossing gain control system is disclosed herein. The system comprises a gain control unit for amplifying an input signal to an output signal, a zero-crossing monitoring circuit for monitoring the input signal or output signal, and a register for latching the digital control signal and generating a gain control signal that controls the gain control unit. The system may further comprise a maximum write time setting circuit for generating a write signal. The digital control signal is written into the register when a zero-crossing state is monitored or a maximum write time since a change occurred on of the digital control signal is expired. An automatic gain control system is also disclosed herein and further comprises a peak detecting circuit for detecting the level of output signal, a logic circuit for lowering or restoring the digital control signal according to the result from the peak detecting circuit.

Abstract: The present disclosure discloses a low drop-out voltage regulator and an electronic device comprising the same. The present disclosure also discloses a method for converting a power supply voltage to a regulated output voltage. The low drop-out voltage regulator comprises a pass device controllable to convert a power supply voltage to a regulated output voltage; and a controller configured to receive an input signal and to provide a driving signal to the control terminal of the pass device based on the input signal, wherein when the input signal is within a predetermined range, the driving signal turns the pass device ON, and the power supply voltage charges the output voltage; and wherein when the input signal is without the predetermined range, the driving signal turns the pass device OFF, and the power supply voltage stops charging the output voltage.

Abstract: The present disclosure discloses a switching mode power supply with constant peak current mode control. During the operation of the switching mode power supply, in one hand, the current flowing through a high-side switch is sensed and compared to a current reference signal to control the turning off of the high-side switch; in the other hand, the output voltage is sensed and compared to a voltage reference signal to control the turning on of the high-side switch. In addition, the current reference signal may be adjusted to a lower value when the switching mode power supply enters light load condition. By using the above control method, the system performance is highly increased.

Abstract: A phase-shift dimming circuit for LED controller having a delay signal generator configured to receive a PWM input signal, and to provide a plurality of pairs of set signal and reset signal, the set signal and the reset signal respectively having pulses; and a plurality of latches configured to respectively receive the plurality of pairs of set signal and reset signal to generate a plurality of PMW output signals, each of the PWM output signals having pulses, and wherein the rising edge of the pulses of the PWM output signals is based on the corresponding set signal pulses, and the falling edge of the pulses of the PWM output signals is based on the corresponding reset signal pulses.

Abstract: A switching mode power supply with a multi-mode controller is provided. The switching mode power supply may include a transformer having a primary winding and a secondary winding to supply power to a load. A feedback circuit may be included to generate a feedback signal that varies in relation to the load on the secondary winding. The multi-mode controller may include a switching circuit, a frequency control circuit and a current limiting circuit. The switching circuit may be coupled to the primary winding to control current flow through the primary winding. The frequency control circuit may control a switching frequency of the switching circuit based on the feedback signal. The current limiting circuit may limit current flow through the primary winding by causing the switching circuit to suspend current flow through the primary winding when the current reaches a peak current limit that is set based on the feedback signal.

Abstract: A failure detector circuit for detecting status of a protected circuit, the failure detector circuit having an operating cycle, has an enabling signal generator, a comparator circuit, a delay circuit. The enabling signal generator enables the comparator for an enable time in each operating cycle. The comparator circuit compares an output of the protected circuit with a reference signal. The delay circuit receives an output signal of the comparator to decide whether a failure occurred within a give delay time.

Abstract: A switching regulator configured to provide an output voltage comprises a power stage, an error correction circuit, a comparator, an ON-time generator and a logic circuit. The error correction circuit generates an error correction voltage based on a reference voltage and a feedback voltage representative of the output voltage. The comparator compares the feedback voltage with the difference between the reference voltage and the error correction voltage, and generates a comparison signal. The ON-time generator is configured to provide an ON-time signal. The logic circuit generates a logic control signal to control the power stage based on the comparison signal and the ON-time signal.

Abstract: An integrated circuit for implementing a switch-mode power converter is disclosed. The integrated circuit comprises at least a first semiconductor die having an electrically quiet surface, a second semiconductor die for controlling the operation of said first semiconductor die stacked on said first semiconductor die having said electrically quiet surface and a lead frame structure for supporting said first semiconductor die and electrically coupling said first and second semiconductor dies to external circuitry.

Abstract: A switch mode power supply system has a constant on-time signal generator, a logic circuit, a feedback circuit, a first ramp signal generator, a second ramp signal generator, a switch circuit having a power switch, and a comparator. A feedback signal from the feedback circuit is compensated by the first ramp signal generator, and a reference signal is compensated by the second ramp signal generator. The comparator compares the compensated feedback signal with the compensated reference signal to indicate an off time of the power switch while the constant on-time signal generator decides the on-time of the power switch.

Abstract: An audio amplifier and a method of operating such an amplifier are disclosed. The audio amplifier includes a switch disabling controller and/or an output set-point controller. The switch disabling controller is configured to disable switching of an output switch circuit or other switch circuit while an input signal represents at least relative silence. The output set-point controller is configured to bring and/or hold first and second switch nodes toward and/or at a set-point voltage while the input signal represents at least relative silence.

Abstract: In one embodiment, a current sensing circuit includes a differential current sensing amplifier adapted for sensing a voltage drop across a main transistor, the differential current sensing amplifier being adapted for providing a switched current output to a timing circuit which is adapted for providing a timing signal to one or more switching current sample-and-hold circuits based on a current waveform of the switched current output, and the one or more switching current sample-and-hold circuits, each of which are adapted for producing a substantially continuous output current. In another embodiment, a method for detecting a current includes driving a main transistor with a first current, driving one or more sensing transistors with a second current, measuring a sensing inductor current of the one or more sensing transistors, and determining the first current based on the sensing inductor current, wherein the sensing inductor current is related to the first current.

Abstract: A no-load detecting circuit and the method thereof are disclosed. The no-load detecting circuit may be applied in switching mode power supplies or other circuits. The no-load detecting circuit comprises: a variable resistance circuit coupled in series to a load of the switching mode power supply; and a first comparison circuit coupled to the variable resistance circuit to receive the voltage across the variable resistance circuit, wherein based on the comparison of the voltage across the variable resistance circuit and a first threshold, the first comparison circuit generates a no-load detecting signal indicative of the load status; wherein the equivalent resistance of the variable resistance circuit varies based on the varying of the load of the switching mode power supply.

Abstract: In one embodiment, a modular master chip includes an output module, a phase control module in communication with the output module, the phase control module including a master chip switch, wherein the phase control module is adapted for regulating the master chip switch at one or more interleaved clock speeds with one or more phase shifts, and a control module in communication with the output module and the phase control module, the control module being adapted for monitoring an amount of current drawn by a current load, determining one or more interleaved clock speeds, sending the one or more interleaved clock speeds, and regulating a scalable amount of current supplied to the current load by adjusting a number of output modules contributing to the scalable amount of current supplied to the current load. More methods and systems are described according to other embodiments.

Abstract: Apparatus, systems, and methods related to controlling multiple strings of light emitting diodes (LEDs) are disclosed. An apparatus may include internal current limiter circuits that are each coupled in series with an associated string of LEDs and are configured to at least partially regulate the current through the associated string of LEDs. The apparatus may also be configured to control external current limiter circuits that are each coupled in series with a corresponding internal current limiter circuit and the string of LEDs associated with the corresponding internal current limiter circuit.

Abstract: A fast startup switching converter comprises a first switch, a second switch, a third switch, a first capacitor, and a controller controlling the ON and OFF switching of the second and third switches. The first terminal of the first switch is coupled to the input terminal of the switching converter, the second terminal is coupled to the first terminal of the second switch. The first terminal of the third switch is coupled to the second terminal of the first switch and the first terminal of the second switch. The first capacitor is coupled to the second terminal of the third switch and the controller to provide a power supply voltage for the controller. The switching converter charges the first capacitor through the first and third switches in a first working state, and transfers energy to a load through the first and second switches in a second working state.

Abstract: A method of driving a lamp that uses a DC to AC inverter that is connected to a primary winding of a transformer is disclosed. The inverter frequency is variable, and in one embodiment, may be controlled by a voltage controlled oscillator. Circuitry is included that monitors the phase relationship between a voltage across a secondary of the transformer and a current through the primary of the transformer. The circuitry monitors the phase relationship and adjusts the inverter frequency, such as by adjusting voltage controlled oscillator, so that the phase relationship is maintained at a predetermined relationship.