Dialog Semiconductor Gmbh

Nan Shi

Xiaoyan Wang

Guang Feng

Clarita Chiting Knoll

Haiju Li

Liang Yan

Chenglong Zhang

Laiqing Ping

Chuanyang Wang

Naidong Xu

The feedback loop of a switching power converter controller is provided with an averaging circuit that averages either an output voltage, an error signal, or a control voltage. Regardless of which feedback signal is averaged, the averaging occurs over a first cycle of a rectified input voltage to form an averaged signal that is used by the feedback loop in a subsequent cycle of the rectified input voltage.

Switching power converter with improved power factor correction via feedback signal averaging

A system for improving a power factor (PF) of a power converter in signal communication with a rectifier and an electromagnetic interference capacitor is disclosed. The system includes a controller and a threshold detector. The threshold detector is configured to measure and compare a rectified voltage against a threshold voltage and the controller is configured to set the power converter to a stop-mode. The power converter is set to the stop-mode at a stop-time that is less than a first zero-crossing time. The controller is further configured to set the power converter to a run-mode at a time that is past the first zero-crossing time.

System and method for improving power factor and THD of a switching power converter

An adaptive pulse frequency modulation for a switching power converter is provided that varies the switching frequency across a cycle of a rectified input voltage for the switching power converter From a beginning of the cycle of the rectified input voltage, the switching frequency decreases from a maximum value to a minimum value at a mid-point of the cycle and then increases from the mid-point back to the maximum value at an end of the cycle.

Switching power converter with adaptive pulse frequency modulation

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.

Improving THD for a direct AC LED lighting device

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.

Digital dimming solution for LED applications including a phase-cut dimmer

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.

Dimmer multi-fire to increase direct AC LED device efficiency

A single configuration terminal of a device is used to configure multiple operating parameters of the device based on a resistor and a capacitor selectively connected to the configuration terminal. The device includes a detection circuit configured to monitor a voltage signal at the configuration terminal to determine multiple values in response to a regulated current source providing a current to the configuration terminal selectively connected to the resistor and the capacitor in parallel, and configure multiple operating parameters based on the determined values. A method for configuring operating parameters using a single configuration terminal of a device includes providing a current to the configuration terminal selectively connected to a resistor and a capacitor in parallel, monitoring a voltage signal at the configuration terminal, determining multiple values based on the monitoring, and configuring multiple operating parameter based on the determined values.

Selection of multiple configuration settings using a single configuration terminal

A direct AC LED lighting device is provided with a low-pass filter for filtering a threshold time in which a post diode bridge voltage exceeds an LED threshold voltage during a current AC half cycle for the post diode bridge voltage.

Reducing jitter in a direct AC LED lighting device

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.

Switching power converter with magnetizing current shaping

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.

High efficiency flicker attenuator for lighting

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.

Time based AC line detection

A multi-mode control scheme for an LED lamp system uses the detected firing angle of an AC input voltage waveform to select from multiple regulation modes. In operation, a current controller compares the detected firing angle to one or more specified thresholds and selects the appropriate regulation scheme based on the comparison result. When the detected firing angle is less than a first firing angle threshold, the controller employs a current shaping regulation mode. When the detected firing angle is greater than a second firing angle threshold, the controller employs a switching cycle-I Peak modulation regulation mode. And when the detected firing angle is greater than the first firing angle threshold and less than the second firing angle threshold, the controller employs a hybrid regulation mode.

Multi-mode control for solid state lighting

An LED lamp comprises one or more LEDs and an LED driver receiving an input signal from a dimmer switch indicative of an amount of dimming for the LED lamp. The LED driver controls regulated current through the one or more LEDs based on the input signal such that an output light intensity of the one or more LEDs substantially corresponds to the amount of dimming for the LED lamp. A regulated output provides operating power for the LED driver. A controller regulates the regulated output to power the LED driver. The controller selects a power source for charging the regulated output from two or more power sources, and the regulated output is charged using the power source selected by the controller.

Powering internal components of LED lamps using dissipative sources

Intelligent control of a solid state lamp when coupled to a trailing edge phase cut dimmer switch is provided. On and off cycles of the lamp's power stage switch are enabled during a period when the energy in the bulk capacitor is at its highest levels. During this period a bleeder circuit does not have to be enabled, which results in a greater operational efficiency as compared with normal switching schemes for trailing edge dimmers.

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Campbell, CA, United States of America

Nan Shi