Abstract: A switching power converter is provided that uses at least two peak current thresholds. In particular, the switching power converter clamps a desired peak current to not fall below a low peak current threshold value while a rectified input voltage is decreasing and to not fall below a high peak current threshold value subsequent to zero crossing times for an AC input voltage.

Abstract: An interface for communicating between two device is provided that includes an interface input for receiving an input signal as well as a comparator circuit coupled to the interface input. The comparator circuit is adapted to provide a clock signal and a data signal based on the input signal to a first memory device having a first input for receiving the data signal and a second input for receiving the clock signal.

Abstract: Systems, devices, and methods for dimming of solid state lighting reduce ripple and flicker at low load dimming levels (low LED current, lower light levels) yet provide full power to the load at high load dimming levels (high LED current, higher light levels) thereby reducing power loss compared to conventional dimming techniques. When dimming to lower light levels a flicker resisting metal oxide semiconductor field effect transistor (MOSFET) connected to the LED operates in linear mode such that the relationship of its drain-source voltage to the LED current is resistive to provide flicker reduction. Conversely, at higher light levels the flicker resisting MOSFET is operated in saturation mode such that full power is supplied to the LED as flicker reduction is less needed. The disclosed techniques also reduce undershoot and overshoot of the LED voltage during transitions in dimming control from high to low and low to high respectively.

Abstract: A line ripple compensation technique is provided for a switching power converter operating in both a pulse frequency mode of operation and a pulse width modulation mode of operation.

Abstract: History-based valley mode switching techniques and systems are provided to reduce the frequency spreading of switching noise in a switching power converter.

Abstract: Systems, methods, and apparatus for a circuit with power factor correction (PFC) are disclosed. In one or more embodiments, the disclosed method comprises providing, by a single-stage power converter, a delay in phase between a peak current command and a rectified input voltage such that a phase of a transformer current intentionally lags behind a phase of the rectified input voltage to maintain a power factor (PF) level and a total harmonic distortion (THD) level for the single-stage power converter. In one or more analog embodiments, a resistor and a capacitor are implemented into a conventional single-stage power converter to provide the delay in phase between the peak current command and the rectified input voltage. In one or more digital embodiments, a controller within a conventional single-stage power converter exclusively provides the delay in phase between the peak current command and the rectified input voltage.

Abstract: A switching power converter is provided with an overvoltage protection circuit that softly switches on a power bus switch during a soft-start period responsive to a device connecting to a data cable for receiving power over a power bus coupled to the power bus switch.

Abstract: A power switch transistor for a switching power converter is maintained on during a re-startup period by a zener breakdown voltage following a fault condition for the switching power converter. A source voltage from the power switch transistor is used to charge a VCC capacitor that stores a power supply voltage for a controller for the switching power converter.

Abstract: An adaptive valley mode switching power converter is provided that switches on a power switch within valley periods of a resonant voltage oscillation for the power switch. Each valley period is determined with regard to a valley threshold voltage.

Abstract: A switching power converter may include a power switch coupled to a primary winding of a transformer, and a primary controller configured to turn on and off the power switch, a synchronous rectifier switch coupled to a secondary winding of a transformer, and a synchronous rectifier controller configured to turn on and off the synchronous rectifier switch. The synchronous rectifier controller may monitor a voltage across the synchronous rectifier switch. The synchronous rectifier controller may determine a period of a resonant oscillation of the voltage across the synchronous rectifier switch following at least one cycling off of the synchronous rectifier switch. The synchronous rectifier controller may adjust the minimum off-time period for the synchronous rectifier switch based on the period of the resonant oscillation. The synchronous rectifier controller may adaptively adjust a minimum off-time period for the synchronous rectifier switch.

Abstract: A startup circuit is provided for establishing the Vcc voltage level of a switching power converter. The startup circuit uses a switch controller and path switching transistor to provide a two-stage Vcc capacitor charging that reduces startup time while avoiding short circuit damage through the alternate usage of a high impedance charging path and a low-impedance charging path.

Abstract: A universal serial bus (USB) charger provides power to a client device. A USB connector interfaces with a client device and receives a request for the output voltage of the USB charger to be at a specific value. If the requested voltage level is lower than the current output voltage level, the output voltage level is set to the requested level and a bleeder circuit is enabled to discharge the output capacitor of the USB charger.

Abstract: A synchronous rectifier controller for controlling the on and off periods of a synchronous rectifier switch transistor in a switching power converter. In particular, the synchronous rectifier controller is configured to adaptively enable and disable a deglitch filter for filtering a turn-on signal for the synchronous rectifier switch transistor. In this fashion, the synchronous rectifier switch transistor may be switched on more rapidly during periods when the deglitch filter is disabled for greater efficiency yet the switching power converter is protected by the deglitch filter when it is not disabled.

Abstract: A power supply detection system and method for determining the AC mains voltage range when a device (e.g., LED based bulbs) is indirectly connected to the AC mains and the device does not receive the complete sinusoidal AC mains signal. The power supply detection system and method receive an input signal having a first portion that is a sinusoidal signal that generally corresponds to a first portion of the voltage source signal and a second portion that is not a sinusoidal signal that generally corresponds to a second portion of the voltage source signal. A selected reference signal is received, wherein the selected reference signal is synchronized with the input signal. The first portion of the input signal is compared with a corresponding portion of the selected reference signal, and the voltage range of the voltage source is determined based on the comparison.

Abstract: A switching power converter is provided that includes a detector to detect whether a controller power supply voltage has fallen below a threshold voltage during a dormant period in which a power switch is no longer cycling to deliver power to a load. In response to a detection of such a threshold crossing by the detector, a controller powered by the controller power supply voltage is configured to cycle the power switch to replenish the controller power supply voltage.

Abstract: A power system and related methods provide sense resistor fault detection and safe operation of switching power converters and connected devices such as portable electronic devices powered by the switching power converter. The power system detects an open circuit or short circuit condition of the sense resistor and controls output current of the switching power converter to ensure safe operating conditions of the power system and connected equipment. The power system can also detect initial inrush current of the connected equipment and detect a duty cycle of the switching power converter to positively detect a short circuit condition of the sense resistor.

Abstract: A system and method of controlling the data transfer rate of a switching power converter when the switching frequency is below a desired level by using an auxiliary load to at least maintain output regulation.

Abstract: An electronic that includes an integrated circuit (IC) configured to regulate an output voltage for powering a light emitting diode (LED). A first transistor is configured to be switched on or off by the IC to inductively couple or decouple a main power supply bus voltage from a primary winding of a transformer to a secondary winding of the transformer connectable to the LED. A second transistor is coupled between the IC and the main power supply bus voltage, and configured to be switched on or off by the IC to selectively provide an IC power supply input voltage to the IC.

Abstract: A power supply control system delivers regulated power to a load via a delivery cable. The power supply control system includes a power stage operable to deliver power to the load at a first regulated voltage level and a second regulated voltage level. A cable offset voltage unit generates an offset voltage signal representing a drop in voltage across the delivery cable. The offset voltage signal is generated based on a first cable drop compensation value when the power stage is operated to deliver power at the first regulated voltage level and based on a second cable drop compensation value when the power stage is operated to deliver power at the second regulated voltage level. A controller coupled to the power stage and the cable offset voltage unit controls the power stage to deliver the regulated power to the load based at least in part on the offset voltage signal.

Abstract: An data transmission method is provided for transmitting analog data through an isolating device using a calibration input pulse and a data input pulse. The analog data may represent, for example, the desired dimming value for a flyback converter powering a solid state lighting system.