Patents by Inventor Anthony Magrath
Anthony Magrath has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).
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Publication number: 20200302282Abstract: The present disclosure relates to a neuron for an artificial neural network, the neuron comprising: a first dot product engine and a second dot product engine. The first dot product engine is operative to: receive a first set of weights; receive a set of inputs; and calculate the dot product of the set of inputs and the first set of weights to generate a first dot product engine output. The second dot product engine is operative to: receive a second set of weights; receive the set of inputs; and calculate the dot product of the set of inputs and the second set of weights to generate a second dot product engine output; The neuron further comprises a combiner operative to combine the first dot product engine output and the second dot product engine output to generate a combined output, and an activation function module arranged to apply an activation function to the combined output to generate a neuron output.Type: ApplicationFiled: March 19, 2019Publication date: September 24, 2020Applicant: Cirrus Logic International Semiconductor Ltd.Inventors: Anthony MAGRATH, John Paul LESSO
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Patent number: 9525945Abstract: Methods and systems for thermal protection of a voice coil of a loudspeaker. The method involves driving the loudspeaker based on an input signal received at an input terminal and monitoring both a voltage applied to the voice coil and a current flowing through the voice coil. From the monitored voltage and current, an estimate of temperature of the voice coil and an estimate of power dissipation in the voice coil is determined. The method includes estimating the voice coil resistance based on the monitored voltage and current and at least the estimate of temperature is determined based the estimate of resistance. A gain control signal for modulating a gain applied to the input signal is generated as a function of both the estimate of temperature of the voice coil and the estimate of power dissipation in the voice coil.Type: GrantFiled: January 22, 2015Date of Patent: December 20, 2016Assignee: Cirrus Logic, Inc.Inventors: Anthony Magrath, Roberto Napoli
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Publication number: 20150215704Abstract: Methods and systems for thermal protection of a voice coil of a loudspeaker. The method involves driving the loudspeaker based on an input signal received at an input terminal and monitoring both a voltage applied to the voice coil and a current flowing through the voice coil. From the monitored voltage and current, an estimate of temperature of the voice coil and an estimate of power dissipation in the voice coil is determined. The method includes estimating the voice coil resistance based on the monitored voltage and current and at least the estimate of temperature is determined based the estimate of resistance. A gain control signal for modulating a gain applied to the input signal is generated as a function of both the estimate of temperature of the voice coil and the estimate of power dissipation in the voice coil.Type: ApplicationFiled: January 22, 2015Publication date: July 30, 2015Applicant: Cirrus Logic International (UK) LimitedInventors: Anthony Magrath, Roberto Napoli
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Publication number: 20100091922Abstract: A sample rate converter circuit receives a first signal at a first sampling frequency and for outputs a second signal, representative of the first signal, having a second sampling frequency.Type: ApplicationFiled: October 13, 2009Publication date: April 15, 2010Inventor: Anthony Magrath
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Patent number: 7567195Abstract: A digital-to-analog converter having an input for receiving a digital input signal during each time period. A plurality of elements are each adapted to produce an analog output in response to an input, and an encoder selects a number of the elements and applies inputs to the selected elements. An analog output signal is then formed by summing outputs of the plurality of elements. The encoder selects the number of elements based on a value of the digital input signal, and selects the elements in a predetermined order from the plurality of elements, starting from an element determined by the elements selected in an immediately preceding time period, and excluding a temporarily omitted one of the plurality of elements.Type: GrantFiled: December 14, 2007Date of Patent: July 28, 2009Assignee: Wolfson Microelectronics plcInventor: Anthony Magrath
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Publication number: 20080143572Abstract: A digital-to-analog converter having an input for receiving a digital input signal during each time period. A plurality of elements are each adapted to produce an analog output in response to an input, and an encoder selects a number of the elements and applies inputs to the selected elements. An analog output signal is then formed by summing outputs of the plurality of elements. The encoder selects the number of elements based on a value of the digital input signal, and selects the elements in a predetermined order from the plurality of elements, starting from an element determined by the elements selected in an immediately preceding time period, and excluding a temporarily omitted one of the plurality of elements.Type: ApplicationFiled: December 14, 2007Publication date: June 19, 2008Inventor: Anthony Magrath
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Publication number: 20070040608Abstract: A feedback controller in a PWM amplifier comprises a signal input for receiving a pulse width modulated (PWM) input signal (Vin) whose duty cycle represents a desired analogue output signal. A feedback loop filter 518 generates a filtered error signal (Vint) comprising a filtered representation of differences between the input signal (Vin) and a feedback signal (Vfb). A comparator (520) compares the filtered error signal with a reference to generate a provisional PWM switching control signal (C) for controlling the PWM amplifier (500). A pulse conditioner (532) receives both the provisional PWM switching control signal (C) and the PWM input signal (X=Vin) and outputs to the amplifier (500) a conditioned PWM switching control signal (Y), modified in accordance with predetermined constraints in relation to the PWM input signal.Type: ApplicationFiled: September 14, 2005Publication date: February 22, 2007Inventors: Anthony Magrath, John Westlake
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Publication number: 20060158359Abstract: The present invention relates to pulse width modulation (PWM) modulators, especially but not exclusively for digital audio applications; and to quantisers and power switching for the same. The present invention provides a pulse width modulation (PWM) modulator or converter having a guard band quantiser arranged to block low level signal inputs to the modulator in order to prevent narrow width output pulses. This arrangement is particularly advantageous when applied to tri-level PWM modulators, but can also be applied to other level PWM modulators such as bi-level for example. Quantisation noise can be reduced by implementing the quantiser in a noise shaper circuit (or possibly a SDM) having loop feedback.Type: ApplicationFiled: April 21, 2005Publication date: July 20, 2006Inventor: Anthony Magrath
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Publication number: 20060083381Abstract: The present invention relates to audio signal processing such as equalisation and spatial enhancement functions. The present invention provides an audio signal processing circuit arrangement for two audio channels, and which combines spatial enhancement or acoustic mixing (crosstalk) cancelling with graphic equalisation functions. This is achieved with a circuit structure having a reduced filter count compared with known cascaded circuits dedicated to each function. The circuit structure processes the sum and difference signals through separate filters and then recombines them to recover the separate channels (adding and subtracting respectively).Type: ApplicationFiled: December 3, 2004Publication date: April 20, 2006Inventor: Anthony Magrath
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Publication number: 20050122241Abstract: The present invention relates to noise shaping, especially although not exclusively for digital audio signal processing; and in particular for PCM-PWM converters in a digital amplifier.Type: ApplicationFiled: February 13, 2004Publication date: June 9, 2005Inventor: Anthony Magrath
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Publication number: 20050123152Abstract: A gain selector for use in a signal processor, particularly a peak limiter, comprising an audio input to receive a signal indicative of an audio signal, and a system gain processor to determine a system gain to be applied to the audio signal, such that the system gain is determined using a predetermined volume gain as well as the signal indicative of the audio signal.Type: ApplicationFiled: April 21, 2004Publication date: June 9, 2005Inventor: Anthony Magrath
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Publication number: 20050058209Abstract: The present invention relates to Class-D amplifiers, and in particular to bit-flipping sigma-delta modulator (SDM) implementations of such amplifiers. Such amplifiers are particularly although not exclusively suitable for audio equipment such as hi-fi and personal music amplifiers. The present invention provides a bit flipping sigma delta modulator (BF SDM) having a multiple feedback loop filter structure. The modulator comprises a quantiser coupled to a bit flipping means, a look ahead quantiser to determine the next quantiser output, and a controller which determines whether to change the output of the bit flipping means. The modulator comprises a feedback loop arranged to add feedback from the output of the modulator to its input. The modulator comprises compensation means to adjust the states of the modulator in order to correct for bit flipping of the output of the quantiser. This adjusts the input to the quantiser to correspond to an input having feedback from a non bit flipped quantiser output.Type: ApplicationFiled: February 4, 2004Publication date: March 17, 2005Inventor: Anthony Magrath