Abstract: A controller of a switching power converter includes a voltage protection circuit that generates a modified supply voltage that does not exceed a predetermined threshold voltage to power one or more components of the controller.

Abstract: A power converter includes a transformer with a primary and a secondary winding and a switch. A controller of the power converter at the primary winding side of the transformer generates a control signal to turn on or turn off the switch, the switch being turned on responsive to the control signal being in a first state and the switch being turned off responsive to the control signal being in a second state. The controller determines current through the primary winding generated while the switch is turned on and indirectly detects an input voltage to the power converter based on the current through the primary winding generated while the switch is turned on. The controller in turn may detect conditions such as a loss of power or brown out at the input of the power converter based on the indirectly detected input voltage.

Abstract: The embodiments herein include a primary-side controller for a switching power converter that is capable of receiving a detection signal from a secondary-side detection circuit indicating that an output voltage has reached a condition. The controller determines the appropriate action once a detection signal has been received by distinguishing whether a dynamic load condition has been placed on the power supply versus other operating conditions.

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: A secondary-side dynamic load detection system and method rapidly identifies when a dynamic load has been placed on the output (e.g., when an electronic device is re-connected to the switching power converter). Once a dynamic load condition has been detected by the secondary side detector, a dynamic load detection signal is communicated from the secondary side of the switching power converter to a switch controller on the primary side. The switch controller can then quickly adapt switching in response to the dynamic load condition.

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 disclosed herein describe a method of a controller of a switching power converter that provides a configurable power factor control method for the switching power converter. In one embodiment, the controller combines power regulation control methods of constant on-time control and constant power control to adjust the power factor of the switching power converter.

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: Selective dimming in a light emitting display device to reduce power consumption. The display device includes a display panel that includes a plurality of light emitting pixels. An image processor is configured to divide an image frame into a plurality of regions and to reduce pixel intensity levels in at least one region of the plurality of regions to generate an adjusted image frame. The at least one region corresponds to a background of the image frame. A display driver converts data for the adjusted image frame into control signals for controlling brightness of the light emitting pixels. The display device may be, for example, an organic light emitting diode (OLED) display device or other type of display device that includes light emitting pixels.

Abstract: A Predictive Power Control (PPC) device within a TCON Bias IC that addresses an overdesign inefficiency and enables a low cost solution. A PPC block utilizes the next frame image data and interacts with a pulse width modulation (PWM) control block of internal regulators to proactively prepare the output voltages of a power regulator for the power requirements in one or more future frames, for example.

Abstract: A light emitting diode (LED) controller provides constant current regulation for a converter circuit providing current to an LED. The LED controller senses an inductor voltage and determines an inductor reset time from the sensed inductor voltage. Based on the determined inductor reset time, a switch on time and a switch period, the LED controller generates a control signal modifying the state of a switch coupling the converter circuit to an input voltage.

Abstract: A start-up circuit in a switch-mode power converter that employs a Zener diode to provide a reference voltage to reduce the power consumption and the size of the start-up circuit. The start-up circuit also includes a coarse current source and a coarse reference voltage signal generator for producing current and reference voltage for initial startup operation of a bandgap circuit. The reference signal and current from coarse current source and the reference voltage signal generator are subject to large process, voltage and temperature (PVT) variations or susceptible to noise from the power supply, and hence, these signals are used temporarily during start-up and replaced with signals from higher performance components. After bandgap circuit becomes operational, the start-up receives voltage reference signal from the bandgap circuit to more accurately detect undervoltage lockout conditions.

Abstract: A switching power converter provides regulated voltage to a load according to a desired regulation voltage. The switching power converter includes a transformer coupled to a switch and a switch controller for generating a control signal to control switching. The switch controller monitors a sensed voltage representing the output voltage of the switching power converter. The switch controller controls switching of the switch to operate the switching power converter in a continuous conduction mode while the sensed output voltage indicates that the output voltage is less than a first threshold voltage. The switch controller controls switching of the switch to operate the switching power converter in a discontinuous conduction mode while the sensed output voltage is above the first threshold voltage.

Abstract: A switching power converter comprises a transformer (110), a switch (108) coupled to the transformer (110), and a switch controller (200) coupled to the switch (108) for generating a switch drive signal (207) to turn on or off the switch (108). The drive current of the switch drive signal (207) is adjusted dynamically according to line or load conditions within a switching cycle and/or over a plurality of switching cycles. The magnitude of the drive current can be dynamically adjusted within a switching cycle and/or over a plurality of switching cycles, in addition to the pulse widths or pulse frequencies of the drive current.

Abstract: An improved discontinuous current mode (DCM) switching power converter that compensates for the effect of dead time. The dead time of the switching power converter is measured during a switching cycle and a baseline on-time for a switch of the switching power converter is determined. The dead time and baseline on-time are used in calculating the desired on-time of the switch during a subsequent switching cycle of the power converter. The desired switch on-time regulates the output voltage to a desired voltage level. The desired switch on-time also maintains the average input current to the power converter in proportion to the input voltage, thereby improving the power factor of the switching power.

Abstract: In a switching power converter, no-load condition is detected based on a variety of parameters including the output current, primary current, transformer reset time, and switching period. Once the no-load condition is detected, the switching power converter enters stand-by mode, in which the reference voltage corresponding to the target regulated output voltage of the switching power converter is lowered to a low stand-by value or the switching power converter is shut down for a predetermined duration. As a result, power loss during the stand-by mode of the switching power converter can be reduced significantly.

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: A dimming controller for an LED lamp controls dimming using an adaptive filter to reduce or eliminate perceivable flickering and to provide smooth transitions during active dimming. During stable conditions, the adaptive filter operates with a relatively narrow bandwidth to filter noise that may lead to perceivable flickering. During active or startup conditions, the adaptive mapping filter operates with a high bandwidth to provide a quick response to the dimmer switch.

Abstract: A dimmable light emitting lamp configured to interface with cat-ear dimmer switches. The lamp includes one or more light emitting devices. The lamp also includes circuitry configured to receive an input voltage and provide regulated current to the one or more light emitting devices. The input voltage has a first voltage pulse that does not represent a dimming level of a dimmer switch and a second voltage pulse that represents the dimming level of the dimmer switch. The circuitry determines a first duration corresponding to a length of the first voltage pulse and a second duration corresponding to a length of the second voltage pulse responsive to first duration. The circuitry adjusts the regulated current to the light emitting devices according to the second duration to adjust output light intensity of the light emitting devices.

Abstract: The embodiments disclosed herein describe a method of a power controller for monitoring for unsafe operating conditions of a drive transistor in a switching power converter of a LED lamp system by predicting the power dissipation of the drive transistor based on knowledge of the current through the drive transistor and a continuous observation of the voltage across the drive transistor. When the drive transistor approaches unsafe operating conditions, the power controller turns off the drive transistor.