Abstract: A high efficiency amplifier system may include multiple output stages cooperatively operating to produce an amplified output signal. The amplifier system may be used in an audio system. The amplifier system may include a non-switchmode amplifier stage cooperatively operating with a switchmode amplifier stage to generate the amplifier output signal. The non-switchmode amplifier stage may selectively enable and disable the switchmode amplifier stage to optimize efficient operation. In addition, the switchmode amplifier stage may include multiple switching stages operated with interleave. The switching stages may be controlled to balance current output of the respective switching stages based on a measured current flow in at least one of the switching stages.

Abstract: A high efficiency amplifier system may include multiple output stages cooperatively operating to produce an amplified output signal. The amplifier system may be used in an audio system. The amplifier system may include a non-switchmode amplifier stage cooperatively operating with a switchmode amplifier stage to generate the amplifier output signal. The non-switchmode amplifier stage may selectively enable and disable the switchmode amplifier stage to optimize efficient operation. In addition, the switchmode amplifier stage may include multiple switching stages operated with interleave. The switching stages may be controlled to balance current output of the respective switching stages based on a measured current flow in at least one of the switching stages.

Abstract: An audio amplifier is operated in an audio system with optimized source impedance to minimize distortion in a loudspeaker that is paired with the audio amplifier. The audio amplifier provides an amplified audio signal to drive the loudspeaker. A variable output impedance of the audio amplifier is controlled using a feedback control loop to allow negative output impedance at low frequencies that changes to positive output impedance at higher frequencies. The change from negative output impedance to positive output impedance occurs at a determined threshold frequency or determined transitional frequency band.

Abstract: An amplifier system for a power converter includes at least a first switching device and a second switching device formed in an integrated circuit in a substrate of a semiconductor. The first and second switching devices may be formed in a half bridge configuration and may be cooperatively switchable to generate an amplified output signal on an output node of the semiconductor. A resistor and a capacitor may be coupled in parallel between a power supply input node and a substrate node included in the semiconductor. The capacitor may be selectively charged to a de-biasing voltage during a switching cycle of the first and second switching devices to reverse bias a parasitic switching device appearing in the integrated circuit.

Abstract: An amplifier system for a power converter includes at least a first switching device and a second switching device formed in an integrated circuit in a substrate of a semiconductor. The first and second switching devices may be formed in a half bridge configuration and may be cooperatively switchable to generate an amplified output signal on an output node of the semiconductor. A resistor and a capacitor may be coupled in parallel between a power supply input node and a substrate node included in the semiconductor. The capacitor may be selectively charged to a de-biasing voltage during a switching cycle of the first and second switching devices to reverse bias a parasitic switching device appearing in the integrated circuit.

Abstract: A switching DC to AC power converter includes an automatic zero voltage switching (ZVS) mode controller. The automatic zero voltage switching mode controller may adjust a ZVS dead-time in accordance with a range of load currents being supplied by the power converter that range from quiescent conditions to a predetermined loading level of the power converter. The variable ZVS dead-time may be larger nearer to quiescent conditions, and become progressively smaller as load currents increase. Outside a predetermined range of load currents, the variable ZVS dead-time may be disabled or minimized.

Abstract: A high efficiency amplifier system may include multiple output stages cooperatively operating to produce an amplified output signal. The amplifier system may be used in an audio system. The amplifier system may include a non-switchmode amplifier stage cooperatively operating with a switchmode amplifier stage to generate the amplifier output signal. The non-switchmode amplifier stage may selectively enable and disable the switchmode amplifier stage to optimize efficient operation. In addition, the switchmode amplifier stage may include multiple switching stages operated with interleave. The switching stages may be controlled to balance current output of the respective switching stages based on a measured current flow in at least one of the switching stages.

Abstract: A high efficiency amplifier system may include multiple output stages cooperatively operating to produce an amplified output signal. The amplifier system may be used in an audio system. The amplifier system may include a non-switchmode amplifier stage cooperatively operating with a switchmode amplifier stage to generate the amplifier output signal. The non-switchmode amplifier stage may selectively enable and disable the switchmode amplifier stage to optimize efficient operation. In addition, the switchmode amplifier stage may include multiple switching stages operated with interleave. The switching stages may be controlled to balance current output of the respective switching stages based on a measured current flow in at least one of the switching stages.

Abstract: An amplifier having improved distortion characteristics is set forth. The amplifier includes an interleaved PWM amplifier that generates interleaved PWM pulses in response to a modified input signal and one or more carrier signals. The interleaved PWM pulses of the amplifier are used to drive a power stage, such as an opposed current power stage. The amplifier also includes an interleaved PWM generator that provides interleaved PWM pulses in response to the modified input signal and one or more further carrier signals. The carrier signals used by the PWM generator may differ in phase from the carrier signals used by the interleaved PWM amplifier to generate its interleaved PWM pulses. One or more feedback circuits are employed in the generation of the modified input signal. More particularly, the feedback circuit(s) generates the modified input signal based on an input signal that is to be amplified and the interleaved PWM pulses of the interleaved PWM generator.

Abstract: A triangle waveform generator is set forth that comprises a capacitive element, a regulator, and a control circuit. The regulator is configured to charge the capacitive element in responsive to a first control signal and to discharge the capacitive element in response to a second control signal. The control circuit is responsive to a reference waveform to generate the first and second control signals. In one example, the control circuit generates the first and second control signals in response to the amplitude, frequency, phase, and symmetry of the reference waveform.

Abstract: An amplifier having improved distortion characteristics is set forth. The amplifier includes an interleaved PWM amplifier that generates interleaved PWM pulses in response to a modified input signal and one or more carrier signals. The interleaved PWM pulses of the amplifier are used to drive a power stage, such as an opposed current power stage. The amplifier also includes an interleaved PWM generator that provides interleaved PWM pulses in response to the modified input signal and one or more further carrier signals. The carrier signals used by the PWM generator may differ in phase from the carrier signals used by the interleaved PWM amplifier to generate its interleaved PWM pulses. One or more feedback circuits are employed in the generation of the modified input signal. More particularly, the feedback circuit(s) generates the modified input signal based on an input signal that is to be amplified and the interleaved PWM pulses of the interleaved PWM generator.

Abstract: An audio amplifier is operated in an audio system with optimized source impedance to minimize distortion in a loudspeaker that is paired with the audio amplifier. The audio amplifier provides an amplified audio signal to drive the loudspeaker. A variable output impedance of the audio amplifier is controlled using a feedback control loop to allow negative output impedance at low frequencies that changes to positive output impedance at higher frequencies. The change from negative output impedance to positive output impedance occurs at a determined threshold frequency or determined transitional frequency band.

Abstract: A system for controlling the delay applied to one branch of a pulse width modulation amplifier. The delay typically incorporated whether input signal level is low and diminished when the input signal level increases. The system may be implemented using a switch, a level detector and a timer, which in conjunction determine whether the delay unit is included in the branch or bypassed. The system may also use a programmable delay that can adjust the period of delay applied or be programmed to operate as a pass-through where delay is no longer beneficial for providing high signal quality.

Abstract: A system is described for powering a wirelessly controlled electric system, such as a sound or security system, via a preexisting power source within an existing building structure. The wirelessly controlled electric system may receive power from the preexisting power source via an adaptor that may be inserted between the preexisting power source and at least one preexisting electric device. The wirelessly controlled electric system may also include a switch for directing the supply of power from the preexisting power source to the preexisting electric device. An electric system controller may direct the operation of the wirelessly controlled electric system. The electric system controller may also direct the switch between a conducting and a non-conducting state to supply power from the preexisting power source to the preexisting electric device.

Abstract: An amplifier having improved distortion characteristics is set forth. The amplifier includes an interleaved PWM amplifier that generates interleaved PWM pulses in response to a modified input signal and one or more carrier signals. The interleaved PWM pulses of the amplifier are used to drive a power stage, such as an opposed current power stage. The amplifier also includes an interleaved PWM generator that provides interleaved PWM pulses in response to the modified input signal and one or more further carrier signals. The carrier signals used by the PWM generator may differ in phase from the carrier signals used by the interleaved PWM amplifier to generate its interleaved PWM pulses. One or more feedback circuits are employed in the generation of the modified input signal. More particularly, the feedback circuit(s) generates the modified input signal based on an input signal that is to be amplified and the interleaved PWM pulses of the interleaved PWM generator.

Abstract: An amplifier having improved distortion characteristics is set forth. The amplifier includes an interleaved PWM amplifier that generates interleaved PWM pulses in response to a modified input signal and one or more carrier signals. The interleaved PWM pulses of the amplifier are used to drive a power stage, such as an opposed current power stage. The amplifier also includes an interleaved PWM generator that provides interleaved PWM pulses in response to the modified input signal and one or more further carrier signals. The carrier signals used by the PWM generator may differ in phase from the carrier signals used by the interleaved PWM amplifier to generate its interleaved PWM pulses. One or more feedback circuits are employed in the generation of the modified input signal. More particularly, the feedback circuit(s) generates the modified input signal based on an input signal that is to be amplified and the interleaved PWM pulses of the interleaved PWM generator.

Abstract: A triangle waveform generator is set forth that comprises a capacitive element, a regulator, and a control circuit. The regulator is configured to charge the capacitive element in responsive to a first control signal and to discharge the capacitive element in response to a second control signal. The control circuit is responsive to a reference waveform to generate the first and second control signals. In one example, the control circuit generates the first and second control signals in response to the amplitude, frequency, phase, and symmetry of the reference waveform.

Abstract: An amplifier having improved distortion characteristics is set forth. The amplifier includes an interleaved PWM amplifier that generates interleaved PWM pulses in response to a modified input signal and one or more carrier signals. The interleaved PWM pulses of the amplifier are used to drive a power stage, such as an opposed current power stage. The amplifier also includes an interleaved PWM generator that provides interleaved PWM pulses in response to the modified input signal and one or more further carrier signals. The carrier signals used by the PWM generator may differ in phase from the carrier signals used by the interleaved PWM amplifier to generate its interleaved PWM pulses. One or more feedback circuits are employed in the generation of the modified input signal. More particularly, the feedback circuit(s) generates the modified input signal based on an input signal that is to be amplified and the interleaved PWM pulses of the interleaved PWM generator.

Abstract: A triangle waveform generator is set forth that comprises a capacitive element, a regulator, and a control circuit. The regulator is configured to charge the capacitive element in responsive to a first control signal and to discharge the capacitive element in response to a second control signal. The control circuit is responsive to a reference waveform to generate the first and second control signals. In one example, the control circuit generates the first and second control signals in response to the amplitude, frequency, phase, and symmetry of the reference waveform.

Abstract: A series resonant Dc-DC converter powers an audio amplifier as a load. The series resonant DC-DC converter may include a power input stage, a switching stage, a series resonant stage, a transformer stage and a power output stage. The series resonant DC-DC converter further may include a clamping stage and a leakage inductance canceling stage. The clamping stage may operate to clamp an excess voltage generated at least by a leakage inductance and a parasitic capacitance. The leakage inductance canceling stage may operate to generate a voltage drop corresponding to a voltage drop generated by the leakage inductance. The generated voltage drop may be subject to clamping. The clamping stage may operate under all load conditions without any influence of the leakage inductance. As a result, the series resonant converter may achieve improved load regulation.