Abstract: A switching power converter is provided with an overvoltage protection circuit that monitors the differential data signal voltages in a data interface such as a USB data interface powering a load device to detect soft short conditions.

Abstract: A first charging path is provided for the charging of an a bootstrap capacitor that stores a driver power supply voltage for driving an active clamp switch transistor in a flyback converter. The first charging path couples charge from an active clamp capacitor to charge the bootstrap capacitor. A power supply capacitor stores a power supply voltage for a controller of a power switch for the flyback converter. A second charging path couples charge from the power supply capacitor to charge the bootstrap capacitor.

Abstract: Systems, devices, and methods are provided to enable power converters to use two or more sensing elements to reliably detect a short circuit (or soft-short circuit) existing in the power converter and distinguish these conditions from other operating conditions, such as low voltage conditions or normal operating conditions. The disclosed embodiments enable the accurate detection of fault conditions, such as short circuits or soft short conditions, using a number of sensing elements, such as sense resistors and the inherent resistance of switching devices, while preventing the detection of false positives due to other factors such as low input voltage.

Abstract: A switching power converter is provided with a phase-shifting RC network for phase-shifting a divided version of a drain voltage of a power switch transistor into a phase-shifted voltage. A comparator compares the phase-shifted voltage to a DC bias voltage to detect peaks and valleys during resonant oscillations of the drain voltage of the power switch transistor.

Abstract: An output current calibration is disclosed to increase the accuracy and precision of the constant-current mode for a flyback converter.

Abstract: An isolated switching power converter communication channel is provided that comprises a pair of capacitors. A transmitter on a first side of a transformer for the converter transmits a transmitter signal over a first one of the capacitors. The transmitter also transmits a complement of the transmitter signal over a second one of the capacitors. A receiver on a second side of the transformer recovers a signal responsive to a high-pass-filtered difference of the received signals from the pair of capacitors.

Abstract: A direct AC LED lighting device is provided with a variable current source and a controller. The controller controls the variable current source to conduct a THD compensation current while an LED string in the direct AC lighting device is not conducting to improve power factor and reduce the THD.

Abstract: A device for determining impedance at a data pin of a communication interface. In one embodiment, the device includes a current source configured to selectively inject a test current to the data pin. The device also includes a sensing circuit for sensing a first test voltage corresponding to a voltage at the data pin without the test current injected, and a second test voltage corresponding to another voltage at the data pin with the test current injected. The sensing circuit determines the impedance at the data pin based on the first test voltage and the second test voltage.

Abstract: A switching power converter is configured to control switching noise by implementing a plurality of pulse width modulation modes of operation. The peak current in each pulse width modulation mode of operation is controlled so that an output power for the switching power converter is continuous with regard to transitions between the pulse width modulation modes.

Abstract: A switching power converter is disclosed that communicates a thermal alarm to a mobile device over a data channel in a data cable for charging the mobile device.

Abstract: A direct charging method is provided that alerts a mobile device when a switching power converter is operating in a constant-current mode to alert the mobile device of an output current without the use of a secondary-side current sense resistor.

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 that adaptively changes the on-time period for an auxiliary switch transistor to locate a boundary between sufficient and insufficient energy.

Abstract: A system and method for controlling a light output from a LED-based lighting solution is provided that may receive phase-cut AC signals and/or external digital control signals. The invention is capable of receiving both a phase-cut AC signal and an external digital control signal simultaneously and providing a desired light output from a LED-based lighting solution. The system generally includes a power source electronically connected to one or more dimmers and an AC power output of the dimmer connected to a solid state lighting device such as an LED. The system is capable of receiving signals from a wired and/or wireless external digital control device to additionally control the desired light output from a LED-based lighting solution.

Abstract: A flyback converter controller is provided with a single terminal through which the flyback converter controller senses for over-voltage faults for an input voltage and also senses for open circuit faults for an auxiliary winding. A first voltage divider provides a divided version of the input voltage to the single terminal. The controller compares a voltage for the single terminal to at least one over-voltage threshold to detect the over-voltage fault for the input voltage.

Abstract: An output voltage calibration circuit and technique is disclosed to increase the accuracy and precision of the constant-voltage mode for a flyback converter.

Abstract: A flyback converter control architecture is provided in which primary-only feedback techniques are used to ensure smooth startup and detection of fault conditions. During steady-state operation, secondary-side regulation is employed. In addition, current limits are monitored during steady-state operation using primary-only feedback techniques to obviate the need for a secondary-side current sense resistor.

Abstract: The embodiments disclosed herein describe a set of fault detection circuits for LED circuits in an LED channel. A first fault detection circuit is configured to detect a short fault across one or more LEDs. A second fault detection circuit is configured to detect an open fault across an LED. A third fault detection circuit is configured to detect a short across an LED channel transistor. A fourth fault detection circuit is configured to detect an LED channel sense resistor open fault. A fifth fault detection circuit is configured to detect if the LED channel is being intentionally unused. These fault detect circuits can be implemented in a fault detection integrated circuit coupled to the LED channel.

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 direct AC LED lighting device is provided with a controller that switches off a bleeder circuit following an initial rising edge for a post diode bridge voltage. The controller measures a first delay between a zero crossing for the post diode bridge voltage and the initial rising edge to estimate a triggering voltage for a leading edge dimmer switch. The controller determines a second delay following the initial rising edge responsive to the estimate of the triggering voltage. The controller may thus switch on the bleeder circuit at an expiration of the second delay so that bleeder circuit is only on for a duration sufficient to develop a voltage difference across the leading edge dimmer switch to equal the triggering voltage just as the post diode bridge voltage satisfies an LED threshold voltage.