Patent application number | Description | Published |
20080278230 | Systems and Methods for Correcting Errors Resulting from Component Mismatch in a Feedback Path - Systems and methods for minimizing performance degradation due to component mismatch in the feedback path of a digital PWM amplifier feedback loop. One embodiment comprises a digital pulse width modulated (PWM) amplifier with feedback. The amplification subsystem receives a digital audio signal and produces an analog output signal. The feedback loop produces a feedback signal based on the filtered analog output signal and modifies the digital audio signal based on the feedback signal. The feedback loop includes a filter configured to filter the analog output signal and correction circuitry configured to correct component mismatch errors introduced by the filter. In one embodiment, the correction circuitry receives a measurement of a power supply voltage, multiplies the measured voltage by a gain and adds the scaled measurement to the feedback signal to correct for the component mismatch errors. | 11-13-2008 |
20090027117 | Low-Noise, Low-Distortion Digital PWM Amplifier - Systems and methods for performance improvements in digital switching amplifiers using low-pass filtering to reduce noise and distortion. In one embodiment, a digital pulse width modulation (PWM) amplifier includes a signal processing plant configured to receive and process an input audio signal. The amplifier also includes a low-pass filter configured to filter audio signals output by the plant. The filtered output of the plant is added to the input audio signal as feedback. The plant may consist of a modulator and power switch, a noise shaper, or any other type of plant. An analog-to-digital converter (ADC) may be provided to convert the output audio signal to a digital signal. Filtering may be implemented before or after the ADC, and a decimator may be placed after the ADC if it is an oversampling ADC. | 01-29-2009 |
20090027118 | Digital PWM Amplifier Having a Low Delay Corrector - Systems and methods for performance improvements in digital switching amplifiers using a low delay corrector. In one embodiment, a digital pulse width modulation (PWM) amplifier includes a signal processing plant configured to receive and process an input audio signal. The amplifier also includes a low delay corrector configured to receive signals output by the plant. The output of the low delay corrector is added to the input audio signal as feedback. The plant may consist of a modulator and power switch, a noise shaper, or any other type of plant. An analog-to-digital converter (ADC) may be provided to convert the output audio signal to a digital signal. Filtering may be implemented before or after the ADC, and a decimator may be placed after the ADC if it is an oversampling ADC. | 01-29-2009 |
20090058549 | Systems and Methods to Minimize Startup Transients in Class D Amplifiers - Systems and methods for minimizing startup transients in digital audio controllers that may result in audible artifacts in the output of an audio amplification system. One embodiment comprises a digital PWM amplifier that includes a mechanism for controlling the amount of dead time in the audio output signal. When the amplifier starts up, the PWM signals provided to the output stage are simultaneously deasserted (i.e., there is dead time) for most of each switch period. The amount of dead time is gradually reduced over a series of switch periods until a nominal operating amount of dead time in each switch period is reached. Thus, the PWM signals are slowly ramped up from having a very large percentage of dead time (e.g., nearly 100%) to having a very small percentage of dead time (e.g., 1-2% to prevent shoot-through.) | 03-05-2009 |
20090169022 | SYSTEMS AND METHODS FOR IMPROVED OVER-CURRENT CLIPPING - Systems and methods for implementing over-current protection in amplifiers are provided, including systems, methods and devices for specifying a clip level at which to clip an audio signal in response to an over-current condition being detected. In an embodiment, the clip level is reduced while the over-current condition is being detected. Once the over-current condition is no longer detected, the clip level is maintained for a specified period before allowing the clip level to be increased. In an embodiment, the specified period, for which the clip level is maintained before the clip level is allowed to be increased, starts when the over-current condition is no longer detected, and ends when each of N immediately preceding sample(s) of the audio signal are not clipped to the clip level, where N is an integer, and N≧1. After an over-current condition is no longer detected, and after the clip level has been maintained for the specified period, the clip level can be increased if an over-current condition is not detected for a sample and the clip level is below a specified maximum clip level. | 07-02-2009 |
20090302938 | LOW DELAY CORRECTOR - A low delay corrector (LDC) unit includes a non-linear function generator and a filter. The nonlinear function generator receives a first signal and outputs a second signal in dependence on the first signal and a transfer function of the nonlinear function generator. The filter is fed in dependence on the second signal output by the nonlinear function generator. The first signal received by the nonlinear function generator is derived in dependence on an input signal provided to an input of the LDC unit and an output of the filter. An output of the LDC unit is derived in dependence on the first signal received by the nonlinear function generator and the second signal output by the nonlinear function generator. | 12-10-2009 |
20100164406 | SWITCHING POWER CONVERTER CONTROL WITH TRIAC-BASED LEADING EDGE DIMMER COMPATIBILITY - In at least one embodiment, a controller allows triac-based dimmer to properly function and dim a load whose voltage is regulated by a switching power converter. In at least one embodiment, the switching power converter includes a switch to control voltage conversion of an input voltage to the switching power converter, wherein phase delays are introduced in the input voltage by a triac-based dimmer during a dimming period. In at least one embodiment, the controller is configured to control the switch of the switching power converter to establish an input resistance of the switching power converter during a dimming portion of the input voltage, wherein the input resistance allows the triac-based dimmer to phase modulate a supply voltage to the dimmer so that an output voltage of the dimmer has a substantially uninterrupted phase delay during each half-cycle of the supply voltage during the dimming period. | 07-01-2010 |
20100253305 | SWITCHING POWER CONVERTER CONTROL WITH SPREAD SPECTRUM BASED ELECTROMAGNETIC INTERFERENCE REDUCTION - Power control systems generate electromagnetic interference (EMI). In at least one embodiment, a power control system includes a switching power converter and a controller that utilizes a spread spectrum strategy to reduce peak EMI values of the power control system. The controller generates a power regulation, switch control signal to control an input voltage to output voltage conversion by the switching power converter. The controller modulates the period of the control signal in accordance with the spread spectrum strategy. The spread spectrum strategy is an intentional plan to spread the spectrum of the control signal to reduce peak EMI values, and, thus, reduce the potential for degradation in performance, a malfunction, or failure of an electronic circuit caused by the EMI. The controller also modulates a pulse width of the switch control signal in response to modulation of the period of the control signal to provide power factor correction. | 10-07-2010 |
20100284547 | SYSTEMS AND METHODS TO MINIMIZE STARTUP TRANSIENTS IN CLASS-D AMPLIFIERS - Systems and methods for minimizing startup transients in digital audio controllers that may result in audible artifacts in the output of an audio amplification system. One embodiment comprises a digital PWM amplifier that includes a mechanism for controlling the amount of dead time in the audio output signal. When the amplifier starts up, the PWM signals provided to the output stage are simultaneously deasserted (i.e., there is dead time) for most of each switch period. The amount of dead time is gradually reduced over a series of switch periods until a nominal operating amount of dead time in each switch period is reached. Thus, the PWM signals are slowly ramped up from having a very large percentage of dead time (e.g., nearly 100%) to having a very small percentage of dead time (e.g., 1-2% to prevent shoot-through.) | 11-11-2010 |
20120044018 | SYSTEMS AND METHODS FOR IMPROVED OVER-CURRENT CLIPPING - Systems and methods for implementing over-current protection include reducing a clip level while an over-current condition is being detected. Once the over-current condition is no longer detected, the clip level is maintained for a specified period before allowing the clip level to be increased. In an embodiment, the specified period, for which the clip level is maintained before the clip level is allowed to be increased, starts when the over-current condition is no longer detected, and ends when each of N immediately preceding sample(s) of the audio signal are not clipped to the clip level, where N is an integer ≧1. After an over-current condition is no longer detected, and after the clip level has been maintained for the specified period, the clip level can be increased if an over-current condition is not detected for a sample and the clip level is below a specified maximum clip level. | 02-23-2012 |
20120242242 | Color Coordination Of Electronic Light Sources With Dimming And Temperature Responsiveness - A lighting system includes one or more methods and systems to control the color spectrum of a lamp in response to both temperature and dim levels. In at least one embodiment, the lighting system includes a controller to control a correlated color temperature (CCT) and intensity of the lamp by independently adjusting currents to electronic light sources based on a dim level of the lighting system and temperature of the lighting system. The controller controls a first current to a first set of LEDs and a second current to a second set of LEDs. The control of the first current by the controller is jointly dependent on a dim level and temperature in the lighting system. In at least one embodiment, the control of the second current is dependent on the dim level or the dim level and temperature. | 09-27-2012 |
20120274225 | Controller Customization System With Phase Cut Angle Communication Customization Data Encoding - A controller is configured to generate one or more power control signals for a lamp to supply power to the lamp from a supply voltage. The controller is further configured to receive customization data encoded in the supply voltage. Thus, in at least one embodiment, the controller receives the customization data via one or more power terminals of the lamp. Phase cut angles in the supply voltage provided to the controller encode the customization data, and each phase cut angle encodes N symbols of data. N is an integer greater than or equal to one (1). In at least one embodiment, the customization data alters the controller from one state to another state in accordance with data represented by phase cuts in the supply voltage that encode the customization data. Examples of customization data include calibration data and configuration data. | 11-01-2012 |
20120299501 | Switching Power Converter Control With Triac-Based Leading Edge Dimmer Compatibility - In at least one embodiment, a controller allows triac-based dimmer to properly function and dim a load whose voltage is regulated by a switching power converter. In at least one embodiment, the switching power converter includes a switch to control voltage conversion of an input voltage to the switching power converter, wherein phase delays are introduced in the input voltage by a triac-based dimmer during a dimming period. In at least one embodiment, the controller is configured to control the switch of the switching power converter to establish an input resistance of the switching power converter during a dimming portion of the input voltage, wherein the input resistance allows the triac-based dimmer to phase modulate a supply voltage to the dimmer so that an output voltage of the dimmer has a substantially uninterrupted phase delay during each half-cycle of the supply voltage during the dimming period. | 11-29-2012 |
20120306407 | Primary-Side Control Of A Switching Power Converter With Feed Forward Delay Compensation - An electronic system includes controller to control a switching power converter to provide power to a load. To control the amount of power provided to the load, in at least one embodiment, the controller senses a current value representing a current in the switching power converter and detects when the current value reaches a target peak value. However, due to delays in the controller and/or the switching power converter, the detected target peak value will not be the actual current peak value generated by the switching power converter. In at least one embodiment, the controller adjusts the detected target peak value with a post-detection delay compensation factor to generate a delay compensated current value that more accurately represents an actual peak current value associated with the current in the switching power converter. | 12-06-2012 |
20140252981 | Utilizing Secondary-Side Conduction Time Parameters of a Switching Power Converter to Provide Energy to a Load - A power distribution system includes controller of a switching power converter to control the switching power converter and determine one or more switching power converter control parameters. In at least one embodiment, the switching power converter utilizes a transformer to transfer energy from a primary-side of the transformer to a secondary-side of the transformer. In at least one embodiment, the switching power converter control parameters includes a secondary-side conduction time delay that represents a time delay between when the primary-side ceases conducting a primary-side current and the secondary-side begins to conduct a secondary-side current. In at least one embodiment, determining and accounting for this secondary-side conduction time delay increases the prediction accuracy of the secondary-side current value and accurate delivery of energy to a load when the controller does not directly sense the secondary-side current provided to the load. | 09-11-2014 |