Patents by Inventor Douglas James Wallace MacFarlane
Douglas James Wallace MacFarlane 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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Patent number: 9872103Abstract: A host device for use with a removable peripheral apparatus having a microphone, and to the biasing circuitry for said microphone. The host device may have a device connector for forming a mating connection with a respective peripheral connector. A source of bias is arranged to supply an electrical bias to a device microphone contact of the device connector via a biasing path. A capacitor is connected between a reference voltage node and a capacitor node of the biasing path. A first switch is located between the capacitor node and the device microphone contact. Detection circuitry detects disconnection of the peripheral connector and device connector; and control circuitry controls the switch to disable the biasing path.Type: GrantFiled: May 10, 2017Date of Patent: January 16, 2018Assignee: Cirrus Logic, Inc.Inventors: Andrew James Howlett, Graeme Gordon Mackay, Douglas James Wallace MacFarlane
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Publication number: 20170245052Abstract: A host device for use with a removable peripheral apparatus having a microphone, and to the biasing circuitry for said microphone. The host device may have a device connector for forming a mating connection with a respective peripheral connector. A source of bias is arranged to supply an electrical bias to a device microphone contact of the device connector via a biasing path. A capacitor is connected between a reference voltage node and a capacitor node of the biasing path. A first switch is located between the capacitor node and the device microphone contact. Detection circuitry detects disconnection of the peripheral connector and device connector; and control circuitry controls the switch to disable the biasing path.Type: ApplicationFiled: May 10, 2017Publication date: August 24, 2017Applicant: Cirrus Logic International Semiconductor Ltd.Inventors: Andrew James HOWLETT, Graeme Gordon MACKAY, Douglas James Wallace MACFARLANE
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Patent number: 9661434Abstract: A host device for use with a removable peripheral apparatus having a microphone, and to the biasing circuitry for said microphone. The host device may have a device connector for forming a mating connection with a respective peripheral connector. A source of bias is arranged to supply an electrical bias to a device microphone contact of the device connector via a biasing path. A capacitor is connected between a reference voltage node and a capacitor node of the biasing path. A first switch is located between the capacitor node and the device microphone contact. Detection circuitry detects disconnection of the peripheral connector and device connector; and control circuitry controls the switch to disable the biasing path.Type: GrantFiled: November 3, 2016Date of Patent: May 23, 2017Assignee: Cirrus Logic, Inc.Inventors: Andrew James Howlett, Graeme Gordon Mackay, Douglas James Wallace MacFarlane
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Publication number: 20170078814Abstract: A host device for use with a removable peripheral apparatus having a microphone, and to the biasing circuitry for said microphone. The host device may have a device connector for forming a mating connection with a respective peripheral connector. A source of bias is arranged to supply an electrical bias to a device microphone contact of the device connector via a biasing path. A capacitor is connected between a reference voltage node and a capacitor node of the biasing path. A first switch is located between the capacitor node and the device microphone contact. Detection circuitry detects disconnection of the peripheral connector and device connector; and control circuitry controls the switch to disable the biasing path.Type: ApplicationFiled: November 3, 2016Publication date: March 16, 2017Applicant: Cirrus Logic International Semiconductor Ltd.Inventors: Andrew James HOWLETT, Graeme Gordon MACKAY, Douglas James Wallace MACFARLANE
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Patent number: 9490765Abstract: A host device for use with a removable peripheral apparatus having a microphone, and to the biasing circuitry for said microphone. The host device may have a device connector for forming a mating connection with a respective peripheral connector. A source of bias is arranged to supply an electrical bias to a device microphone contact of the device connector via a biasing path. A capacitor is connected between a reference voltage node and a capacitor node of the biasing path. A first switch is located between the capacitor node and the device microphone contact. Detection circuitry detects disconnection of the peripheral connector and device connector; and control circuitry controls the switch to disable the biasing path.Type: GrantFiled: September 24, 2015Date of Patent: November 8, 2016Assignee: Cirrus Logic, Inc.Inventors: Andrew James Howlett, Graeme Gordon Mackay, Douglas James Wallace MacFarlane
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Patent number: 9300212Abstract: Methods and apparatus for control of DC-DC converters, especially in valley current mode. The DC-DC converter is operable so that a low side supply switch may be turned off, before the high side supply switch is turned on. During the period when both switches are off the current loop control remains active and the change in inductor (L) current is emulated. One embodiment uses a current sensor for lossless current sensing and emulates the change in inductor current by holding the value of the output of the current sensor (ISNS) at the time that the low side switch turns off and adding an emulated ramp signal (VISLP) until the inductor current reaches zero. Embodiment employing a pulse-skip mode of operation based on a minimum conduction time are also disclosed. The invention enables a seamless transition from Continuous Conduction Mode the Discontinuous Conduction Mode and Pulse Skipping and provide converters that are efficient at low current loads.Type: GrantFiled: July 29, 2013Date of Patent: March 29, 2016Assignee: Cirrus Logic International Semiconductor Ltd.Inventors: Andrew Notman, Mark McCloy-Stevens, Douglas James Wallace MacFarlane, Holger Haiplik
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Publication number: 20160056786Abstract: A host device for use with a removable peripheral apparatus having a microphone, and to the biasing circuitry for said microphone. The host device may have a device connector for forming a mating connection with a respective peripheral connector. A source of bias is arranged to supply an electrical bias to a device microphone contact of the device connector via a biasing path. A capacitor is connected between a reference voltage node and a capacitor node of the biasing path. A first switch is located between the capacitor node and the device microphone contact. Detection circuitry detects disconnection of the peripheral connector and device connector; and control circuitry controls the switch to disable the biasing path.Type: ApplicationFiled: September 24, 2015Publication date: February 25, 2016Inventors: Andrew James Howlett, Graeme Gordon Mackay, Douglas James Wallace MacFarlane
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Patent number: 9148722Abstract: A host device for use with a removable peripheral apparatus having a microphone, and to the biasing circuitry for said microphone. The host device may have a device connector for forming a mating connection with a respective peripheral connector. A source of bias is arranged to supply an electrical bias to a device microphone contact of the device connector via a biasing path. A capacitor is connected between a reference voltage node and a capacitor node of the biasing path. A first switch is located between the capacitor node and the device microphone contact. Detection circuitry detects disconnection of the peripheral connector and device connector; and control circuitry controls the switch to disable the biasing path.Type: GrantFiled: April 3, 2014Date of Patent: September 29, 2015Assignee: Cirrus Logic International Semiconductor Ltd.Inventors: Andrew James Howlett, Graeme Gordon MacKay, Douglas James Wallace MacFarlane
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Publication number: 20140307910Abstract: A host device for use with a removable peripheral apparatus having a microphone, and to the biasing circuitry for said microphone. The host device may have a device connector for forming a mating connection with a respective peripheral connector. A source of bias is arranged to supply an electrical bias to a device microphone contact of the device connector via a biasing path. A capacitor is connected between a reference voltage node and a capacitor node of the biasing path. A first switch is located between the capacitor node and the device microphone contact. Detection circuitry detects disconnection of the peripheral connector and device connector; and control circuitry controls the switch to disable the biasing path.Type: ApplicationFiled: April 3, 2014Publication date: October 16, 2014Applicant: Wolfson Microelectronics plcInventors: Andrew James Howlett, Graeme Gordon MacKay, Douglas James Wallace MacFarlane
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Patent number: 8699726Abstract: An apparatus comprising a capacitive transducer, for example a MEMS microphone. A first voltage generator is connected to receive a first voltage (VDD*) and generate a second voltage (VCP) for biasing the capacitive transducer. A control circuit is adapted to, in use, control the first voltage (VDD*) based on a calibration value, wherein a different calibration value would lead to a different first voltage level and the calibration value is set such that an input signal of known amplitude produces an output signal of predetermined amplitude.Type: GrantFiled: December 30, 2009Date of Patent: April 15, 2014Assignee: Wolfson Microelectronics plcInventors: Colin Findlay Steele, Douglas James Wallace MacFarlane
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Patent number: 8541993Abstract: Methods and apparatus for control of DC-DC converters, especially in valley current mode. The DC-DC converter is operable so that a low side supply switch may be turned off, before the high side supply switch is turned on. During the period when both switches are off the current loop control remains active and the change in inductor (L) current is emulated. One embodiment uses a current sensor for lossless current sensing and emulates the change in inductor current by holding the value of the output of the current sensor (ISNS) at the time that the low side switch turns off and adding an emulated ramp signal (VISLP) until the inductor current reaches zero. Embodiment employing a pulse-skip mode of operation based on a minimum conduction time are also disclosed. The invention enables a seamless transition from Continuous Conduction Mode the Discontinuous Conduction Mode and Pulse Skipping and provide converters that are efficient at low current loads.Type: GrantFiled: July 22, 2010Date of Patent: September 24, 2013Assignee: Wolfson Microelectronics plcInventors: Andrew Notman, Mark McCloy-Stevens, Douglas James Wallace MacFarlane, Holger Haiplik
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Patent number: 8508288Abstract: A method of generating a voltage supply (Vout+, Vout?) from a single input supply (+VDD), comprising connecting at least one flying capacitor (Cf) to at least one reservoir capacitor (CR1, CR2) and to the input supply in repeated cycles so as to generate a voltage on said reservoir capacitor, the cycles differing between at least two modes so that each mode generates a different voltage on said reservoir capacitor the method including changing from an existing one of said modes to enter a new one of said modes during operation, and operating in at least one transitional mode for a period prior to entering fully said new mode.Type: GrantFiled: September 4, 2012Date of Patent: August 13, 2013Assignee: Wolfson Microelectronics plcInventor: Douglas James Wallace MacFarlane
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Publication number: 20120326771Abstract: A method of generating a voltage supply (Vout+, Vout?) from a single input supply (+VDD), comprising connecting at least one flying capacitor (Cf) to at least one reservoir capacitor (CR1, CR2) and to the input supply in repeated cycles so as to generate a voltage on said reservoir capacitor, the cycles differing between at least two modes so that each mode generates a different voltage on said reservoir capacitor the method including changing from an existing one of said modes to enter a new one of said modes during operation, and operating in at least one transitional mode for a period prior to entering fully said new mode.Type: ApplicationFiled: September 4, 2012Publication date: December 27, 2012Inventor: Douglas James Wallace MacFarlane
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Patent number: 8264273Abstract: A method of generating a voltage supply (Vout+, Vout?) from a single input supply (+VDD), comprising connecting at least one flying capacitor (Cf) to at least one reservoir capacitor (CR1, CR2) and to the input supply in repeated cycles so as to generate a voltage on said reservoir capacitor, the cycles differing between at least two modes so that each mode generates a different voltage on said reservoir capacitor the method including changing from an existing one of said modes to enter a new one of said modes during operation, and operating in at least one transitional mode for a period prior to entering fully said new mode.Type: GrantFiled: December 8, 2008Date of Patent: September 11, 2012Assignee: Wolfson Microelectronics plcInventor: Douglas James Wallace MacFarlane
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Publication number: 20110050185Abstract: Methods and apparatus for control of DC-DC converters, especially in valley current mode. The DC-DC converter is operable so that a low side supply switch may be turned off, before the high side supply switch is turned on. During the period when both switches are off the current loop control remains active and the change in inductor (L) current is emulated. One embodiment uses a current sensor for lossless current sensing and emulates the change in inductor current by holding the value of the output of the current sensor (ISNS) at the time that the low side switch turns off and adding an emulated ramp signal (VISLP) until the inductor current reaches zero. Embodiment employing a pulse-skip mode of operation based on a minimum conduction time are also disclosed. The invention enables a seamless transition from Continuous Conduction Mode the Discontinuous Conduction Mode and Pulse Skipping and provide converters that are efficient at low current loads.Type: ApplicationFiled: July 22, 2010Publication date: March 3, 2011Inventors: Andrew Notman, Mark McCloy-Stevens, Douglas James Wallace MacFarlane, Holger Haiplik
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Publication number: 20100277152Abstract: A method of generating a voltage supply (Vout+, Vout?) from a single input supply (+VDD), comprising connecting at least one flying capacitor (Cf) to at least one reservoir capacitor (CR1, CR2) and to the input supply in repeated cycles so as to generate a voltage on said reservoir capacitor, the cycles differing between at least two modes so that each mode generates a different voltage on said reservoir capacitor the method including changing from an existing one of said modes to enter a new one of said modes during operation, and operating in at least one transitional mode for a period prior to entering fully said new mode.Type: ApplicationFiled: December 8, 2008Publication date: November 4, 2010Inventor: Douglas James Wallace MacFarlane
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Publication number: 20100166228Abstract: An apparatus comprising a capacitive transducer, for example a MEMS microphone. A first voltage generator is connected to receive a first voltage (VDD*) and generate a second voltage (VCP) for biasing the capacitive transducer. A control circuit is adapted to, in use, control the first voltage (VDD*) based on a calibration value, wherein a different calibration value would lead to a different first voltage level and the calibration value is set such that an input signal of known amplitude produces an output signal of predetermined amplitude.Type: ApplicationFiled: December 30, 2009Publication date: July 1, 2010Inventors: Colin Findlay Steele, Douglas James Wallace MacFarlane