Abstract: A switching power converter provides regulated voltage to a load. The switching power converter comprises a transformer including a first primary winding coupled to an input voltage, a second primary winding, a secondary winding coupled to an output of the switching power converter, and an auxiliary winding, a first switch coupled to the first primary winding, and a second switch coupled to the secondary primary winding. A controller generates a first control signal to turn the first switch on or off at a first switching frequency, and a second control signal to turn the second switch on or off at a second switching frequency that is higher than the first frequency. During off cycles of the switches, feedback voltage representing the output voltage of the power converter is generated across the auxiliary winding. The controller controls switching of the first switch to regulate the output voltage based on the feedback.

Abstract: An LED driver controls current through an LED string. The LED driver generates a boosted PWM signal to drive a PWM transistor in the LED current path such that the PWM transistor maintains a substantially constant VGS, thus minimizing turn-on impedance of the PWM transistor. A current mirror circuit controls peak LED current when the PWM transistor is on. A trimming circuit includes a set of programmable switches to couple or decouple trimming transistor from the LED current path, and allowing for fine calibration of the LED current. By maintaining a low resistance and compensating for current mismatch in the LED current path, the LED driver provides efficient power performance and robustness that is particularly beneficial in high current applications.

Abstract: A light-emitting diode (LED) lighting fixture is configured to interface a three-way socket and provide at least two levels of output light intensity. A detection unit determines whether one or both input voltages lines of the three-way socket are active and provides a control signal to an LED controller indicating which input voltage lines are active. The LED controller is configured to provide different output current levels to an LED bank based on whether one or both input voltage lines are active. By adjusting the output current level based on which input lines are active, the LED lighting fixture provides at least two output lighting intensity levels. LED lighting fixtures according to various embodiments can therefore serve as a direct replacement for three-way incandescent bulbs.

Abstract: A power converter includes a transformer with a primary and a secondary winding. Feedback and control is maintained on the primary-side while a separate load detection circuit detects dynamic load conditions on the secondary-side. The load detection circuit detects dynamic load conditions at the time when a load is connected to the output of the switching power converter and, in turn, generates an alert signal. A coupling circuit coupled to the load detection circuit at the secondary winding side of the transformer and to the controller at the primary winding side of the transformer transmits the alert signal to the controller. The controller regulates the output voltage based on the feedback signal generated at the primary side of the transformer while detecting and responding to the dynamic load condition based on the alert signal generated at the secondary side of the transformer.

Abstract: Embodiments described herein describe a power supply configured to provide power to an output load via a power supply transformer. The power supply includes a controller configured to operate in a configuration state and an operating state. During the configuration state, the controller receives a configuration signal from a sense circuit coupled to the controller and selects one of a plurality of operating modes from the configuration signal. During the operating state, the controller controls a switch coupled to the transformer based on the selected operating mode and a sense signal received from the sense circuit representative of the power provided to the output load by the power supply. When the switch is closed, current flows from a power source through the transformer, and when the switch is open, current is prevented from flowing from the power source through the transformer.

Abstract: The embodiments herein describe a dynamic metal-oxide-semiconductor field-effect transistor (MOSFET) gate driver system architecture and control scheme. The MOSFET gate driver system dynamically adjusts both the gate driver turn-on-resistance and the gate driver turn-off resistance within a single (i.e., one) switching cycle to reduce electromagnetic interference (EMI) in the system and to minimize the conduction loss of a power MOSFET during operation.

Abstract: A power converter that controls a collector current of a bipolar junction transistor (BJT) by controlling the base current to the BJT after having determined the gain of the BJT. A gain detection block determines a gain of the BJT during a first mode. A current calculation block generates a current setting for the base current based on the gain of the BJT determined by the gain detection block during a second mode distinct from the first mode. In some embodiments, the power converter may be included in a LED lamp system.

Abstract: An LED lamp is provided in which the output light intensity of the LEDs in the LED lamp is adjusted based on the input voltage to the LED lamp. A dimmer control unit detects a type of dimmer switch during a configuration process. Using the detected dimmer type, the dimmer control unit generates control signals appropriate for the detected dimmer type to provide regulated current to the LEDs and to achieve the desired dimming effect. The LED lamp can be a direct replacement of conventional incandescent lamps in typical wiring configurations found in residential and commercial building lighting applications that use conventional dimmer switches.

Abstract: The embodiments herein describe a power converter including a controller that estimates input current of the power converter. The controller estimates the input current without explicitly sensing the input current. The estimated input current can be used in various applications such as regulating power factor and total harmonic distortion as well as estimating current required to maintain proper operation of a dimmer switch in light emitting diode lamp systems.

Abstract: Embodiments disclosed herein describe the use of a power supply to provide power to an LED load. The power supply provides a present output current to the LED, and receives a temperature signal representing the operating temperature of the LED. A target output current is determined, for instance based on the temperature signal. An output current rate of change is determined, and the power supply adjusts the output current to the LED at the determined rate of change until the output current is substantially equal to the target current.

Abstract: The embodiments herein describe a switched mode power converter. In particular, the embodiments herein disclose techniques for reducing power consumption of a synchronous rectifier controller of the switched mode power converter. The switched mode power converter includes a plurality of circuit components that control operation of a synchronous rectifier included in the switched mode power converter. One or more of the circuit components may be disabled to reduce power consumption.

Abstract: A light-emitting diode (LED) lighting fixture is configured to interface a three-way socket and provide three levels of output light intensity. A detection unit determines whether one or both input voltages lines of the three-way socket are active and provides a control signal to an LED controller indicating which input voltage lines are active. The LED controller is configured to provide different output current levels to an LED bank based on whether one or both input voltage lines are active. By adjusting the output current level based on which input lines are active, the LED lighting fixture provides three output lighting intensity levels. LED lighting fixtures according to various embodiments can therefore serve as a direct replacement for three-way incandescent bulbs.

Abstract: A switching regulator comprises a PWM controller that controls switching of a power converter via a PWM control signal. The switching regulator detects load transients in the load driven by the power converter. Responsive to the detection of a load transient, the switching regulator resets a PWM clock synchronously with a fast clock operating at a higher frequency than the PWM clock. By doing so, the switching regulator beneficially responds more quickly to changes in the load than with conventional architectures that utilize only the slower PWM clock. This provides improved transient response without sacrificing power efficiency.

Abstract: The embodiments disclosed herein describe a method of a controller to maintain a substantially constant average output current at the output of a switching power converter. In one embodiment, the controller uses a regulation voltage that corresponds to the primary peak current regulation level to regulate the average output current.

Abstract: A controller integrated circuit (IC) for controlling a power converter uses one or more IC pins having plurality of functions such as configuration of a parameter supported by the controller IC and shutdown protection. Several different functions may be supported by a single IC pin, thereby reducing the number of pins required in the controller IC and also reducing the cost of manufacturing the controller IC. The controller IC may also share a comparison circuit among different pins and the different functions provided by those pins. Use of a shared comparison circuit further reduces the cost of manufacturing the controller IC without sacrificing the performance of the IC.

Abstract: A controller of a switching power converter employs a dynamically adaptive power supply regulation approach that improves low-load and no-load regulation to achieve ultra-low standby power in a switching power converter. Under ultra-low load conditions when a deep-deep pulse width modulation (DDPWM) is applied, the controller decreases the actual on-time of the power switch of the switching power converter by decreasing the “on” duration of the control signal used to turn on or off the power switch, until the “on” duration of the control signal reaches a minimum value. To further reduce the on-time of the power switch, the controller reduces the power applied to the power switch to turn on the switch more slowly, while maintaining the “on” duration of the control signal at a minimum value. The minimum value of the “on” duration of the control signal and the minimum power applied to the switch are dynamically controlled.

Abstract: A LED lamp that includes a LED lamp controller with delayed startup after a fault condition is detected. The type of the fault condition is used in determining a length of the startup delay, such as a number of power cycles during which the LED lamp controller is prevented from completing its configuration. Examples of different types of fault conditions include faults in a supply voltage or faults in a feedback voltage to the LED lamp controller. Fault type information can also be stored in circuitry that retains data and is not reset across the power cycles.

Abstract: An LED lamp is provided in which the output light intensity of the LEDs in the LED lamp is adjusted based on the input voltage to the LED lamp. A dimmer control unit detects a type of dimmer switch during a configuration process. Using the detected dimmer type, the dimmer control unit generates control signals appropriate for the detected dimmer type to provide regulated current to the LEDs and to achieve the desired dimming effect. The LED lamp can be a direct replacement of conventional incandescent lamps in typical wiring configurations found in residential and commercial building lighting applications that use conventional dimmer switches.

Abstract: A controller of a switching power converter sets an actual turn-on time of a switch in the switching power converter in each switching cycle by selecting one of a plurality of valley points of the output voltage of the switching power converter occurring subsequent to the desired turn-on time of the switch. The desired turn-on time of the switch may be calculated according to the regulation scheme employed by the switching power converter. The controller selects one of the plurality of valley points randomly from switching cycle to switching cycle. The controller generates a control signal to turn on the switching power converter at the selected one of the plurality of valley points of the output voltage occurring subsequent to the desired turn-on time.

Abstract: The embodiments herein describe a switched mode power converter. In particular, the embodiments herein disclose a method for powering a synchronous rectifier controller that enables synchronous rectification in the switched mode power converter. The synchronous rectifier controller may be enabled by a regulator circuit or directly from the output voltage.