Patents by Inventor William E. Rader
William E. Rader 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: 20230253956Abstract: A transistor is switched on and off with an on-time that is held constant and an off-time that is varied. When the off-time is detected to be less than a threshold value that is greater than a minimum off-time limit, the on-time is extended. Then the power transistor is switched on and off with the extended on-time that is held constant and the off-time that varies.Type: ApplicationFiled: April 17, 2023Publication date: August 10, 2023Applicant: Silanna Asia Pte LtdInventors: Robert Eric Fesler, William E. Rader, III, Yashovardhan R. Potlapalli
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Patent number: 11664785Abstract: A power transistor is switched on and off with an on-time that is held constant and an off-time that is varied. When the off-time is detected to be less than a threshold value that is greater than a minimum off-time limit, the on-time is extended. Then the power transistor is switched on and off with the extended on-time that is held constant and the off-time that varies.Type: GrantFiled: March 2, 2022Date of Patent: May 30, 2023Assignee: Silanna Asia Pte LtdInventors: Robert Eric Fesler, William E. Rader, III, Yashovardhan R. Potlapalli
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Publication number: 20220190811Abstract: A power transistor is switched on and off with an on-time that is held constant and an off-time that is varied. When the off-time is detected to be less than a threshold value that is greater than a minimum off-time limit, the on-time is extended. Then the power transistor is switched on and off with the extended on-time that is held constant and the off-time that varies.Type: ApplicationFiled: March 2, 2022Publication date: June 16, 2022Applicant: Silanna Asia Pte LtdInventors: Robert Eric Fesler, William E. Rader, III, Yashovardhan R. Potlapalli
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Patent number: 11290090Abstract: A power transistor is switched on and off with an on-time that is held constant and an off-time that is varied. When the off-time is detected to be less than a threshold value that is greater than a minimum off-time limit, the on-time is extended. Then the power transistor is switched on and off with the extended on-time that is held constant and the off-time that varies.Type: GrantFiled: December 15, 2020Date of Patent: March 29, 2022Assignee: Silanna Asia Pte LtdInventors: Robert Eric Fesler, William E. Rader, III, Yashovardhan R. Potlapalli
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Publication number: 20210257998Abstract: A power transistor is switched on and off with an on-time that is held constant and an off-time that is varied. When the off-time is detected to be less than a threshold value that is greater than a minimum off-time limit, the on-time is extended. Then the power transistor is switched on and off with the extended on-time that is held constant and the off-time that varies.Type: ApplicationFiled: December 15, 2020Publication date: August 19, 2021Applicant: Silanna Asia Pte LtdInventors: Robert Eric Fesler, William E. Rader, III, Yashovardhan R. Potlapalli
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Publication number: 20140266123Abstract: The present disclosure includes systems and methods using truncated ramp signal in switching regulators. In one embodiment, a switching regulator includes a truncated ramp generator to produce a truncated ramp signal comprising a ramp component and a constant component. A comparator receives the truncated ramp signal and a first signal, and in accordance therewith, produces a modulation signal. The first signal is based on an output voltage or an output current, and the first signal intersects the constant component of the truncated ramp signal in response to a change in the output voltage or output current, and in accordance therewith, the first switching transistor changes state.Type: ApplicationFiled: March 13, 2013Publication date: September 18, 2014Applicant: QUALCOMM INCORPORATEDInventor: William E. Rader
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Patent number: 7459959Abstract: A plurality of LEDs is driven in parallel, in at least two modes. In a first mode, the LEDs are driven with a first voltage. In subsequent modes, the LEDs are driven with successively higher voltages. The forward voltage drop for each LED is monitored, and the driver switches from the first mode to successive modes based on the largest of the LED forward voltage drops. The current through each LED is controlled by directing a reference current through a first digitally controlled variable resistance circuit, and directing the LED current through a second digitally controlled variable resistance circuit having substantially a known ratio to the first variable resistance circuit and connected in series with the LED. A digital count is altered based on a comparison of the first and second currents, and the first and second variable resistance circuits are simultaneously altered based on the digital count.Type: GrantFiled: November 23, 2004Date of Patent: December 2, 2008Assignee: Semtech CorporationInventors: William E. Rader, Ryan P. Foran
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Patent number: 6836157Abstract: A plurality of LEDs is driven in parallel, in at least two modes. In a first mode, the LEDs are driven with a first voltage. In subsequent modes, the LEDs are driven with successively higher voltages. The forward voltage drop for each LED is monitored, and the driver switches from the first mode to successive modes based on the largest of the LED forward voltage drops. The current through each LED is controlled by directing a reference current through a first digitally controlled variable resistance circuit, and directing the LED current through a second digitally controlled variable resistance circuit having substantially a known ratio to the first variable resistance circuit and connected in series with the LED. A digital count is altered based on a comparison of the first and second currents, and the first and second variable resistance circuits are simultaneously altered based on the digital count.Type: GrantFiled: May 9, 2003Date of Patent: December 28, 2004Assignee: Semtech CorporationInventors: William E. Rader, Ryan P. Foran
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Publication number: 20040233144Abstract: A plurality of LEDs is driven in parallel, in at least two modes. In a first mode, the LEDs are driven with a first voltage. In subsequent modes, the LEDs are driven with successively higher voltages. The forward voltage drop for each LED is monitored, and the driver switches from the first mode to successive modes based on the largest of the LED forward voltage drops. The current through each LED is controlled by directing a reference current through a first digitally controlled variable resistance circuit, and directing the LED current through a second digitally controlled variable resistance circuit having substantially a known ratio to the first variable resistance circuit and connected in series with the LED. A digital count is altered based on a comparison of the first and second currents, and the first and second variable resistance circuits are simultaneously altered based on the digital count.Type: ApplicationFiled: May 9, 2003Publication date: November 25, 2004Inventors: William E. Rader, Ryan P. Foran
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Patent number: 6794926Abstract: A charge pump power supply includes two or more modes of operation. An input protection circuit is connected between an input of the power supply and a voltage source. The input protection circuit regulates the voltage at the input of the power supply, limits current at the input when switching from a weaker mode to a stronger mode, and prevents current reversal when switching from a stronger mode to a weaker mode. In some modes, the power supply continuously provides current to the load, obviating the need for an output capacitor.Type: GrantFiled: December 5, 2002Date of Patent: September 21, 2004Assignee: Semtech CorporationInventors: William E. Rader, David P. Keesor
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Publication number: 20030085752Abstract: A charge pump power supply includes two or more modes of operation. An input protection circuit is connected between an input of the power supply and a voltage source. The input protection circuit regulates the voltage at the input of the power supply, limits current at the input when switching from a weaker mode to a stronger mode, and prevents current reversal when switching from a stronger mode to a weaker mode. In some modes, the power supply continuously provides current to the load, obviating the need for an output capacitor.Type: ApplicationFiled: December 5, 2002Publication date: May 8, 2003Inventors: William E. Rader, David P. Keesor
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Patent number: 6504422Abstract: A charge pump power supply includes two or more modes of operation. An input protection circuit is connected between an input of the power supply and a voltage source. The input protection circuit regulates the voltage at the input of the power supply, limits current at the input when switching from a weaker mode to a stronger mode, and prevents current reversal when switching from a stronger mode to a weaker mode. In some modes, the power supply continuously provides current to the load, obviating the need for an output capacitor.Type: GrantFiled: November 21, 2000Date of Patent: January 7, 2003Assignee: Semtech CorporationInventors: William E. Rader, David P. Keesor
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Patent number: 6377032Abstract: An apparatus and method for virtual current sensing in a DC-DC switched mode power supply. In a fixed frequency implementation, when a switching phase begins, the phase node goes high when the high-side switching transistor is turned on. At this point, a first programmable current source begins charging a current sensing capacitor and the voltage across the capacitor simulates the rising slope of the voltage across a conventional current sensing resistor. Simultaneously, a ramp capacitor beginning at a reference voltage is charged by a second programmable current source. When the sum of the voltages across the two capacitors exceeds an error voltage, the phase node goes low when the drive signal to the transistor is turned off. At this point, a third programmable current source begins discharging the current sensing capacitor and the voltage across the capacitor simulates the falling slope of the current across the conventional resistor.Type: GrantFiled: July 20, 2000Date of Patent: April 23, 2002Assignee: Semtech CorporationInventors: Joseph M. Andruzzi, John Fogg, William E. Rader, III