Patent classifications
H03F1/34
Minimizing startup transients in an audio playback path
A method may be provided for powering up or down a playback path comprising a digital-to-analog converter (DAC) for generating a non-ground-centered analog intermediate voltage centered at a common-mode voltage and coupled to a driver for generating a ground-centered playback path output voltage at an output of the driver wherein the output of the driver is clamped via a finite impedance to a ground voltage. The method may include transitioning continuously or in a plurality of discrete steps the analog intermediate voltage from an initial voltage to the common-mode voltage such that the transitioning is substantially inaudible at the output of the driver. A method for operating an output clamp of an output driver stage of a playback path may include transitioning continuously or in a plurality of discrete steps an impedance of the output clamp in order to match an output offset of the output driver stage in order to minimize audio artifacts appearing at an output of the output driver stage.
Peaking amplifier frequency tuning
A circuit including: input and output nodes and first and second feedback nodes; a first input amplifier having an input connected to the input node and an output connected to the first feedback node; a second input amplifier having an input connected to the input node and an output connected to the second feedback node; a capacitor connecting the first feedback node and the second feedback node; an amplifier having an input connected to the first feedback node and an output connected to the output node; a base feedback amplifier with an input connected to the output node and an output connected to the first feedback node; a tunable feedback amplifier with an input connected to the output node and an output connected to the second feedback node; and a tuning circuit for varying a transconductance of the tunable feedback circuit and operational frequency of the peaking amplifier circuit.
Low Distortion Output Stage for Audio Amplifiers
A circuit and method for an audio op-amp that is configured to minimize crossover distortion between push and pull components of the audio op-amp. The audio op-amp includes an input stage that receives differential input signals and generates an output that amplifies the difference between the input signals. The audio op-amp further includes an output stage that receive the amplified signal and generate an audio output signal for playback by a speaker system. The output stage includes a diamond driver circuit that buffers the input stage from the speaker system, a boost circuit that includes a pair of boosting transistors that amplify the current of the amplified signal, and a biasing circuit that provides bias currents to the transistors of the boost circuit in a manner that minimizes crossover distortion between the boosting transistors.
Low Distortion Output Stage for Audio Amplifiers
A circuit and method for an audio op-amp that is configured to minimize crossover distortion between push and pull components of the audio op-amp. The audio op-amp includes an input stage that receives differential input signals and generates an output that amplifies the difference between the input signals. The audio op-amp further includes an output stage that receive the amplified signal and generate an audio output signal for playback by a speaker system. The output stage includes a diamond driver circuit that buffers the input stage from the speaker system, a boost circuit that includes a pair of boosting transistors that amplify the current of the amplified signal, and a biasing circuit that provides bias currents to the transistors of the boost circuit in a manner that minimizes crossover distortion between the boosting transistors.
Audio signal amplification device
An audio signal amplification device of the disclosure includes: a delta-sigma modulation part configured to resample an input digital audio signal with a quantization number smaller than a quantization number of the digital audio signal; a pulse-width modulation part configured to convert an output signal from the delta-sigma modulation part into a pulse-width modulation signal which sets a gradation of the output signal in an amplitude direction at a gradation of a pulse width; a power amplification part configured to perform power amplification on an output signal from the pulse-width modulation part; a low-pass filter configured to diminish a component higher than a predetermined cutoff frequency, in an output signal from the power amplification part, and to output the resultant signal; and a correction processing part configured to generate a correction signal for correcting the digital audio signal. The correction processing part includes a switch configured to control coupling of the correction processing part to the low-pass filter. When the switch is on, the correction processing part couples a loudspeaker to the low-pass filter, and generates the correction signal.
Audio signal amplification device
An audio signal amplification device of the disclosure includes: a delta-sigma modulation part configured to resample an input digital audio signal with a quantization number smaller than a quantization number of the digital audio signal; a pulse-width modulation part configured to convert an output signal from the delta-sigma modulation part into a pulse-width modulation signal which sets a gradation of the output signal in an amplitude direction at a gradation of a pulse width; a power amplification part configured to perform power amplification on an output signal from the pulse-width modulation part; a low-pass filter configured to diminish a component higher than a predetermined cutoff frequency, in an output signal from the power amplification part, and to output the resultant signal; and a correction processing part configured to generate a correction signal for correcting the digital audio signal. The correction processing part includes a switch configured to control coupling of the correction processing part to the low-pass filter. When the switch is on, the correction processing part couples a loudspeaker to the low-pass filter, and generates the correction signal.
Low voltage high speed CMOS line driver without tail current source
The present invention is directed to electrical circuits and techniques thereof. More specifically, an embodiment of the present invention provides a line driver with transistors directly coupled to the ground, and a bias voltage is coupled common mode resistors of the line driver. There are other embodiments as well.
Low voltage high speed CMOS line driver without tail current source
The present invention is directed to electrical circuits and techniques thereof. More specifically, an embodiment of the present invention provides a line driver with transistors directly coupled to the ground, and a bias voltage is coupled common mode resistors of the line driver. There are other embodiments as well.
SENSOR AMPLIFIER ARRANGEMENT AND METHOD OF AMPLIFYING A SENSOR SIGNAL
A sensor amplifier arrangement includes an amplifier having a signal input to receive a sensor signal and a signal output, and a feedback path that couples the signal output to the signal input, wherein the feedback path includes an anti-parallel circuit of diodes, and a voltage divider including a first and a second divider resistor and a voltage divider tap between the first and the second divider resistor, wherein the voltage divider couples the signal output to a reference potential terminal, and the voltage divider tap is coupled to the anti-parallel circuit of diodes and the anti-parallel circuit of diodes is coupled to the signal input.
SENSOR AMPLIFIER ARRANGEMENT AND METHOD OF AMPLIFYING A SENSOR SIGNAL
A sensor amplifier arrangement includes an amplifier having a signal input to receive a sensor signal and a signal output, and a feedback path that couples the signal output to the signal input, wherein the feedback path includes an anti-parallel circuit of diodes, and a voltage divider including a first and a second divider resistor and a voltage divider tap between the first and the second divider resistor, wherein the voltage divider couples the signal output to a reference potential terminal, and the voltage divider tap is coupled to the anti-parallel circuit of diodes and the anti-parallel circuit of diodes is coupled to the signal input.