Abstract: A feedback control circuit is described herein, comprising: an operational amplifier (op-amp) integrated circuit, wherein a first output of the op-amp provides a feedback error control signal; at least two transistors provided in a feedback path between the first output of the op-amp and an inverting input to the op-amp; and a plurality of discrete electrical components in the feedback path, such that in response to either an increase or decrease of an inverting input voltage at the inverting input that exceeds a predetermined level, at least one of the at least two transistors is turned on, and the feedback control circuit provides the feedback error control signal with an increased slew rate.

Abstract: Described herein is a triangle wave generator circuit for use with a class D amplifier, the triangle wave generator circuit adapted to generate and output a triangle wave signal and comprising: a clock generating circuit adapted to provide a timing signal that generates a period of the output triangle wave; a first current source adapted to provide a first source current at a first magnitude; a first current sink adapted to sink a first sink current at about two times the first magnitude; a DC servo circuit adapted to adjust the first magnitude of the first source current based on a direct current (DC) voltage present in the output triangle wave signal so that the DC voltage on the output triangle wave signal is substantially eliminated; and an output filter circuit adapted to substantially reduce audio frequency noise in the output triangle wave, and generate the output triangle wave signal at a desired peak-to-peak voltage level based on the first source current and first sink current.

Abstract: An inductor is provided, comprising: a first ferrite core piece and a second ferrite core piece, each of which are made of substantially similar materials, exhibit desired electromagnetic properties, and which are fashioned in a substantially similar manner and shape, and wherein each of the first and second ferrite core pieces comprises a substantially planar mating surface, a center post, and a wire core assembly channel, and wherein a first substantially planar mating surface of the first ferrite core piece is adapted to planarly mate with a second substantially planar mating surface of the second ferrite core piece; and a wire core assembly adapted to be substantially self-locating and self-centering about a first or second center post when located in a respective first or second wire core assembly channel.

Abstract: A feedback control circuit is described herein, comprising: an operational amplifier (op-amp) integrated circuit, wherein a first output of the op-amp provides a feedback error control signal; at least two transistors provided in a feedback path between the first output of the op-amp and an inverting input to the op-amp; and a plurality of discrete electrical components in the feedback path, such that in response to either an increase or decrease of an inverting input voltage at the inverting input that exceeds a predetermined level, at least one of the at least two transistors is turned on, and the feedback control circuit provides the feedback error control signal with an increased slew rate.

Abstract: A feedback control circuit is described herein, comprising: an operational amplifier (op-amp) integrated circuit, wherein a first output of the op-amp provides a feedback error control signal; at least two transistors provided in a feedback path between the first output of the op-amp and an inverting input to the op-amp; and a plurality of discrete electrical components in the feedback path, such that in the response to either an increase or decrease of an inverting input voltage at the inverting input that exceeds a predetermined level, will speed up substantially. The feedback control circuit provides the feedback error control signal.

Abstract: An audio amplifier system is described herein, comprising: an amplifier adapted to amplify an audio signal and comprising an output enable/disable input, the amplifier further adapted to receive an output enable signal at the output enable/disable input that enables/disables an output of the amplifier; a Zobel network connected to the output of the audio amplifier and comprising a Zobel capacitor and a Zobel resistor arranged such that they form a high pass frequency filter function and wherein the Zobel network is adapted to be substantially resistive when a frequency of an audio signal output from the audio amplifier is within a first frequency range; a mirroring resistor connected in parallel to the Zobel resistor and adapted to mirror a power that is dissipated in the Zobel resistor, and wherein a printed circuit board upon which the mirroring resistor is located is adapted to conduct heat generated by the mirroring resistor; a negative temperature coefficient (NTC) resistor located in close proximity to

Abstract: A feedback control circuit is described herein, comprising: an operational amplifier (op-amp) integrated circuit, wherein a first output of the op-amp provides a feedback error control signal; at least two transistors provided in a feedback path between the first output of the op-amp and an inverting input to the op-amp; and a plurality of discrete electrical components in the feedback path, such that in the response to either an increase or decrease of an inverting input voltage at the inverting input that exceeds a predetermined level, will speed up substantially. The feedback control circuit provides the feedback error control signal.

Abstract: An audio amplifier system is described herein, comprising: an amplifier adapted to amplify an audio signal and comprising an output enable/disable input, the amplifier further adapted to receive an output enable signal at the output enable/disable input that enables/disables an output of the amplifier; a Zobel network connected to the output of the audio amplifier and comprising a Zobel capacitor and a Zobel resistor arranged such that they form a high pass frequency filter function and wherein the Zobel network is adapted to be substantially resistive when a frequency of an audio signal output from the audio amplifier is within a first frequency range; a mirroring resistor connected in parallel to the Zobel resistor and adapted to mirror a power that is dissipated in the Zobel resistor, and wherein a printed circuit board upon which the mirroring resistor is located is adapted to conduct heat generated by the mirroring resistor; a negative temperature coefficient (NTC) resistor located in close proximity to

Abstract: A rail balancing circuit is described herein for use with a power supply, the RBC comprising: a circuit adapted to respond to over-voltage and under-voltage conditions in the power supply that comprises a positive rail voltage source and a negative rail voltage source, such that any deviation from a balanced condition between the positive rail voltage source and the negative rail voltage source is substantially instantaneously corrected to bring both the positive and negative rail voltage sources back to the balanced condition.

Abstract: A rail balancing circuit is described herein for use with a power supply, the RBC comprising: a circuit adapted to respond to over-voltage and under-voltage conditions in the power supply that comprises a positive rail voltage source and a negative rail voltage source, such that any deviation from a balanced condition between the positive rail voltage source and the negative rail voltage source is substantially instantaneously corrected to bring both the positive and negative rail voltage sources back to the balanced condition.

Abstract: A rail balancing circuit is described herein for use with a power supply, the RBC comprising: a circuit adapted to respond to over-voltage and under-voltage conditions in the power supply that comprises a positive rail voltage source and a negative rail voltage source, such that any deviation from a balanced condition between the positive rail voltage source and the negative rail voltage source is substantially instantaneously corrected to bring both the positive and negative rail voltage sources back to the balanced condition.

Abstract: Described herein are several configurations of Class-D audio amplifiers, including a single-ended and a bridge-tied load (BTL) configuration, in which voltage-mode control and average current-mode control circuitry in feedback loops can be included to control the outputs of the Class-D amplifier to reduce open-loop errors and maintain a relatively high loop gain over an expected audio frequency range. The average current-mode control circuitry monitors current through a resistor common to both a current flow into a positive terminal of a loudspeaker associated with the amplifier and a current flow into a negative terminal of the loudspeaker. The voltage-mode control circuitry works with the average current-mode control circuitry in controlling the output of the Class-D audio amplifier.

Abstract: A multi-channel Class D audio amplifier is provided to substantially reduce channel-to-channel crosstalk by employing in each channel a local triangle ramp generator controlled by a single global digital timing signal. The noise critical timing/integrating capacitor for the triangle ramp generator resides locally in each channel and adjacent to the PWM comparator of that channel and referenced to the local ground of that channel. The amplifier can also include a duty cycle limitation circuit to limit output power availability depending on the impedance of any attached loads (speakers).