Patents by Inventor Joshua William Caldwell
Joshua William Caldwell 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: 20230180390Abstract: Systems and methods for sense resistors are disclosed. In one aspect, an integrated sense resistor includes a plurality of first metal bumps alternating with a plurality of second metal bumps in at least a first lateral direction and a plurality of thin film resistors each disposed between and electrically connected to a pair of adjacent ones of first and second metal bumps. The integrated sense resistor can be configured for sensing a voltage developed by current flowing across the integrated sense resistor for determining a value of the current.Type: ApplicationFiled: November 30, 2022Publication date: June 8, 2023Inventors: Patrick Martin McGuinness, Joshua William Caldwell
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Patent number: 10291128Abstract: A synchronous converter that includes a power source, an inductor, an output terminal, and a control circuit. The control circuit may include: an electronic energizing switch that, when activated, delivers energy from the power source to the inductor; an electronic de-energizing switch that, when activated, delivers energy from the inductor to the output terminal, the electronic de-energizing switch including a body diode; and an electronic pull-down switch that, when activated, turns off the electronic de-energizing switch, redirects current flowing though the body diode of the electronic de-energizing switch, and removes charge from the body diode of the electronic de-energizing switch. The electronic energizing switch and the electronic de-energizing switch may never both be activated at the same time.Type: GrantFiled: December 19, 2017Date of Patent: May 14, 2019Assignee: Linear Technology Holding LLCInventors: Dongwon Kwon, Joshua William Caldwell
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Patent number: 10201052Abstract: Techniques are provided for low, or deep, dimming of a light-emitting diode (LED) load. In an example, a low dimming circuit can include a target current detector configured to provide an output indicative of a target current of a power stage of a pulse width modulated driver, and a control circuit configured to receive a PWM signal of the PWM LED driver, to control a first transition to a first state of a power switch of the power stage during an on-interval of a first PWM cycle of the PWM signal, and to control a second transition to the first state of the power switch using the output of the target current detector during an off interval of the first PWM cycle.Type: GrantFiled: September 22, 2017Date of Patent: February 5, 2019Assignee: Linear Technology Holding, LLCInventors: Lucas Andrew Milner, Joshua William Caldwell
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Patent number: 10136488Abstract: Techniques are provided for low, or deep, dimming of a light-emitting diode (LED) load. In an example, a method of adjusting an initial voltage of a driver circuit for an LED load can include providing current to an LED load from a power stage of the driver during an on-time of a pulse-width modulation (PWM) cycle, receiving error current information of the driver circuit at a low-dimming control circuit of the driver, and adjusting a voltage of an output capacitor coupled to the driver during an off-time of the PWM cycle, the charge adjustment based on the error current information.Type: GrantFiled: October 5, 2017Date of Patent: November 20, 2018Assignee: Linear Technology Holding, LLCInventors: Dongwon Kwon, Joshua William Caldwell
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Patent number: 10123384Abstract: Techniques are provided for low, or deep, dimming of a light-emitting diode (LED) load. In an example, a method for deep dimming a light-emitting diode (LED) load can include, when a current of an inductor does not reach a target current by the end of an on-time of a pulse-width modulation (PWM) switch cycle, and, during an initial on-time of the PWM switch cycle, allowing the current of the inductor to reach the target current during a next “off” time interval of the PWM switch cycle, wherein the inductor is coupled to the LED via a PWM switch, and in response to the current of the inductor reaching the target current before the end of the on-time of a subsequent PWM switch cycle, interrupting energizing of the inductor at the end of the on-time of the PWM switch cycle.Type: GrantFiled: September 22, 2017Date of Patent: November 6, 2018Assignee: Linear Technology Holding, LLCInventors: Lucas Andrew Milner, Joshua William Caldwell, Hezekiel Dakjung Randolph
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Patent number: 9642200Abstract: A method and system of driving an LED load. There is a power stage that is configured to deliver a level of current indicated by a control signal to the LED load when a PWM signal is ON and stop delivering the level of current when the PWM signal is OFF. There is a feedback circuit that is configured to generate the operating point signal, which causes the power stage to deliver a level of current indicated by the control signal, when the PWM signal is ON. A store and hold circuit is configured to store an information indicative of a level of the operating point signal just after the PWM signal is turned OFF and cause the operating point signal to be at that level just before the PWM signal is turned ON.Type: GrantFiled: May 5, 2016Date of Patent: May 2, 2017Assignee: Linear Technology CorporationInventors: Joshua William Caldwell, Dongwon Kwon, Lucas Andrew Milner
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Patent number: 9596728Abstract: A method and system of driving an LED load. A driver is configured to deliver a level of current indicated by a control signal to the LED load when a PWM signal is ON and stop delivering the level of current when the PWM signal is OFF. An output capacitance element is coupled across a differential output of the LED driver. A feedback path, having a store circuit, is configured to store an information indicative of a first voltage level across the output capacitance element as a stored feedback reference signal just after the PWM signal is turned OFF. The feedback path causes the voltage across the output capacitance element to be at the first voltage level just before the PWM signal is turned ON.Type: GrantFiled: May 5, 2016Date of Patent: March 14, 2017Assignee: Linear Technology CorporationInventors: Joshua William Caldwell, Dongwon Kwon, Lucas Andrew Milner
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Publication number: 20160353532Abstract: A method and system of driving an LED load. A driver is configured to deliver a level of current indicated by a control signal to the LED load when a PWM signal is ON and stop delivering the level of current when the PWM signal is OFF. An output capacitance element is coupled across a differential output of the LED driver. A feedback path, having a store circuit, is configured to store an information indicative of a first voltage level across the output capacitance element as a stored feedback reference signal just after the PWM signal is turned OFF. The feedback path causes the voltage across the output capacitance element to be at the first voltage level just before the PWM signal is turned ON.Type: ApplicationFiled: May 5, 2016Publication date: December 1, 2016Applicant: LINEAR TECHNOLOGY CORPORATIONInventors: Joshua William Caldwell, Dongwon Kwon, Lucas Andrew Milner
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Publication number: 20160353537Abstract: A method and system of driving an LED load. There is a power stage that is configured to deliver a level of current indicated by a control signal to the LED load when a PWM signal is ON and stop delivering the level of current when the PWM signal is OFF. There is a feedback circuit that is configured to generate the operating point signal, which causes the power stage to deliver a level of current indicated by the control signal, when the PWM signal is ON. A store and hold circuit is configured to store an information indicative of a level of the operating point signal just after the PWM signal is turned OFF and cause the operating point signal to be at that level just before the PWM signal is turned ON.Type: ApplicationFiled: May 5, 2016Publication date: December 1, 2016Applicant: LINEAR TECHNOLOGY CORPORATIONInventors: Joshua William Caldwell, Dongwon Kwon, Lucas Andrew Milner
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Patent number: 8901904Abstract: A device and method of providing any one of a plurality of desired levels of a regulated signal output to a load is described, wherein each desired level is a function of a corresponding reference signal. The device is configured and the method is designed to (1) store each desired level of the regulated signal output on a switchable storage device; and (2) selectively switch the correct storage device to the output when switching from one regulated state to another so as to establish the desired level of regulated signal output.Type: GrantFiled: July 24, 2009Date of Patent: December 2, 2014Assignee: Linear Technology CorporationInventor: Joshua William Caldwell
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Patent number: 8120335Abstract: An average current mode switching converter is described for providing a regulated output current independent of load conditions, and a regulated output voltage as a function of the load connected to the converter. The converter includes an inductor, a modulator, a feedback loop, and a precharger. The modulator is configured to provide a regulated current through the inductor The feed back loop is coupled between the inductor and the modulator for regulating the current through the inductor. The precharger is configured and arranged so as to provide and maintain a preset minimum current through the inductor independent of the load so as to improve the recovery time of the converter from a step in the desired regulated output current. Also disclosed is a method of providing a regulated output current independent of load conditions at the output of an average current mode switching converter, and a regulated output voltage as a function of the load connected to the output of converter.Type: GrantFiled: March 27, 2009Date of Patent: February 21, 2012Assignee: Linear Technology CorporationInventor: Joshua William Caldwell
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Publication number: 20100244793Abstract: An average current mode switching converter is described for providing a regulated output current independent of load conditions, and a regulated output voltage as a function of the load connected to the converter. The converter comprises: an inductor; a modulator configured to provide a regulated current through the inductor; a feed back loop coupled between the inductor and the modulator for regulating the current through the inductor; and a precharger configured and arranged so as to provide and maintain a preset minimum current through the inductor independent of the load so as to improve the recovery time of the converter from a step in the desired regulated output current. Also disclosed is a method of providing a regulated output current independent of load conditions at the output of an average current mode switching converter, and a regulated output voltage as a function of the load connected to the output of converter.Type: ApplicationFiled: March 27, 2009Publication date: September 30, 2010Applicant: Linear Technology CorporationInventor: Joshua William Caldwell
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Patent number: 7170352Abstract: A circuit for driving a capacitive load is provided. The circuit includes a differential signal sensor and a differential amplifier. The differential amplifier is arranged to drive the capacitive load. Further, the differential amplifier is arranged to receive an output voltage at one input, and to receive a reference voltage at another input. The output voltage is provided at the output of the differential amplifier. Also, the differential amplifier is arranged to receive a bias current. The differential signal sensor is arranged to determine whether the difference between the output voltage and the reference voltage is within a voltage window. If the difference between the output voltage and the reference voltage is inside of the voltage window, the bias current is provided at its normal value. However, if the difference between the output voltage and the reference voltage is outside of the voltage window, the bias current is increased so that the bias current linearly increases with respect to time.Type: GrantFiled: May 4, 2005Date of Patent: January 30, 2007Assignee: National Semiconductor CorporationInventor: Joshua William Caldwell
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Patent number: 6977491Abstract: A current limiting circuit. The current limiting circuit includes a device coupled to an output node of the current limiting circuit. The device is responsive to magnitude of a signal at the output node. Moreover, the device has a first mode and a second mode, depending on the magnitude of the signal. The current limiting circuit also has a regulation component that regulates a voltage at the output node when the device is in the first mode. The current limiting circuit also has an element having a current that limits current at the output node when the device is in the second mode.Type: GrantFiled: October 6, 2003Date of Patent: December 20, 2005Assignee: National Semiconductor CorporationInventors: Joshua William Caldwell, Steven Ashley Martinez
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Patent number: 6969982Abstract: A circuit having a voltage regulated by a reference current. The circuit includes a current feedback loop and a reference current source that is capable of producing a reference current. The current feedback loop includes an output device, a voltage to current converter, and a current feedback element. The voltage to current converter is coupled to the output device. A node of the voltage to current converter is the regulated voltage. The current feedback element is coupled to the voltage to current converter to provide a feedback current from the voltage to current converter to compare with the reference current to produce an error signal that is input to a control terminal of the output device. Thus, the current feedback loop regulates the voltage at the node of the voltage to current converter.Type: GrantFiled: October 3, 2003Date of Patent: November 29, 2005Assignee: National Semiconductor CorporationInventor: Joshua William Caldwell
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Patent number: 6879194Abstract: An active power-on reset (POR) current comparator circuit creates a POR signal for resetting logic devices and masking reference startup signals during the initial power supply ramp of an integrated circuit. The comparator circuit provides a logic level signal (i.e., the POR signal) that will actuate when a bias current is above a predetermined level as compared to another current. The predetermined level for the bias current is set by a ratio established between two resistance levels within the active POR current comparator circuit.Type: GrantFiled: August 25, 2003Date of Patent: April 12, 2005Assignee: National Semiconductor CorporationInventor: Joshua William Caldwell