Patents by Inventor Thomas A. Somerville
Thomas A. Somerville 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: 9793861Abstract: Certain aspects of the present disclosure provide methods and apparatus for implementing an amplification system. The amplification system includes an amplifier comprising differential inputs and an output. The differential inputs include an inverting input and a non-inverting input. The amplification system further includes a feedback path from the output coupled to the inverting input. The feedback path from the output is coupled to at least one of an inverting amplifier or buffer, and the at least one of the inverting amplifier or buffer is further coupled to the non-inverting input.Type: GrantFiled: July 28, 2016Date of Patent: October 17, 2017Assignee: QUALCOMM IncorporatedInventor: Thomas Somerville
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Patent number: 9092041Abstract: A current mirror circuit that is configured to adjust a body to source voltage of an input device in response to a drain to source voltage of an output device is disclosed. In an implementation, the current mirror circuit comprises a current mirror including an input device and an output device coupled together. The current mirror circuit also includes a feedback circuit component coupled between the output of the current mirror and the input device. The feedback circuit component is configured to adjust a body to source voltage of the input device in response to a drain to source voltage of the output device.Type: GrantFiled: July 27, 2012Date of Patent: July 28, 2015Assignee: Maxim Integrated Products, Inc.Inventor: Thomas A. Somerville
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Patent number: 7557551Abstract: The present invention is a high efficiency AM switching voltage regulator used to provide an AM output signal to an AM RF power amplifier, wherein the AM output signal is proportional to an AM input signal. The AM output signal includes an AM output voltage and an AM supply current, which represents a sum of an AM output current and a shunt current The AM output voltage provides an envelope supply voltage to the AM RF power amplifier. The switching voltage regulator includes a switching current regulator coupled to a linear shunt voltage regulator. The switching current regulator provides AM output current for the AM RF power amplifier and a small amount of shunt current for the linear shunt voltage regulator, which regulates the AM output voltage by controlling the shunt current. The switching current regulator regulates the AM supply current in proportion to a time-averaged value of shunt current.Type: GrantFiled: July 14, 2006Date of Patent: July 7, 2009Assignee: RF Micro Devices, Inc.Inventors: Thomas A. Somerville, Michael R. Kay, David C. Dening
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Patent number: 7535204Abstract: The present invention is a switching power converter that includes multiple energy transfer legs feeding a common energy storage circuit. Each energy transfer leg has a unique switching signal with a common switching frequency. The unique switching signals are phase-shifted from each other to minimize generation of switching noise within the passband of a received RF signal. Each unique switching signal has an active state during which energy may be transferred to the energy transfer leg, and an inactive state during which energy may be transferred from the energy transfer leg to the common energy storage circuit.Type: GrantFiled: March 9, 2007Date of Patent: May 19, 2009Assignee: RF Micro Devices, Inc.Inventors: Praveen V. Nadimpalli, Thomas A. Somerville
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Patent number: 6876249Abstract: An adjustable voltage reference circuit (14, 25, 70) that can be adjusted via an external device is disclosed. The circuit is designed to receive, after packaging, a plurality of adjustment inputs (20). These inputs are used by an adjustable voltage cell (21, 26, 71) to produce an adjustment factor. The adjustment factor will then be used by a voltage reference cell (22, 27, 72) to adjust the reference voltage (Vref).Type: GrantFiled: August 13, 2002Date of Patent: April 5, 2005Assignee: Semiconductor Components Industries, LLCInventors: Robert Maigret, Thomas Somerville
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Patent number: 6856189Abstract: A bandgap voltage reference generator may include a BJT (Bipolar Junction Transistor) and a pair of MOSFETs (Metal Oxide Semiconductor Field Effect Transistors) coupled to the BJT. The base-emitter voltage Vbe of the BJT may exhibit a non-linearity with respect to temperature. The difference between gate-source voltages of the pair of MOSFETs exhibits an opposite non-linearity with respect to temperature. The opposite non-linearity reduces the effect of the non-linearity on the output voltage of the bandgap voltage reference generator. The difference in gate-source voltages of the pair of MOSFETs may be determined by the ratio of channel width to channel length of each MOSFET included in the pair of MOSFETs.Type: GrantFiled: May 29, 2003Date of Patent: February 15, 2005Assignee: Standard Microsystems CorporationInventor: Thomas A. Somerville
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Publication number: 20050012554Abstract: Various embodiments of methods and apparatus for an amplifier with wide output voltage swing are disclosed. The amplifier may include multiple output stages, each associated with a distinct supply voltage. Each output stage may contribute current to the output of the amplifier over a range of amplifier output voltages and these ranges may overlap. Each output stage may contribute current until the amplifier output voltage reaches the supply voltage associated with that output stage. The amplifier output may be as great as the largest supply voltage minus a drop equal to Rdson for an output transistor multiplied by the output current. In a CMOS implementation, this voltage drop may be approximately 0.15V. When the amplifier output voltage is close to the supply voltage associated with an output stage, both that output stage and the output stage associated with the next highest supply voltage may contribute to the amplifier output.Type: ApplicationFiled: July 17, 2003Publication date: January 20, 2005Inventors: Thomas Somerville, Klaas Wortel
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Patent number: 6838942Abstract: Various embodiments of methods and apparatus for an amplifier with wide output voltage swing are disclosed. The amplifier may include multiple output stages, each associated with a distinct supply voltage. Each output stage may contribute current to the output of the amplifier over a range of amplifier output voltages and these ranges may overlap. Each output stage may contribute current until the amplifier output voltage reaches the supply voltage associated with that output stage. The amplifier output may be as great as the largest supply voltage minus a drop equal to Rdson for an output transistor multiplied by the output current. In a CMOS implementation, this voltage drop may be approximately 0.15V. When the amplifier output voltage is close to the supply voltage associated with an output stage, both that output stage and the output stage associated with the next highest supply voltage may contribute to the amplifier output.Type: GrantFiled: July 17, 2003Date of Patent: January 4, 2005Assignee: Standard Microsystems CorporationInventors: Thomas A. Somerville, Klaas Wortel
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Publication number: 20040239411Abstract: A bandgap voltage reference generator may include a BJT (Bipolar Junction Transistor) and a pair of MOSFETs (Metal Oxide Semiconductor Field Effect Transistors) coupled to the BJT. The base-emitter voltage Vbe of the BJT may exhibit a non-linearity with respect to temperature. The difference between gate-source voltages of the pair of MOSFETs exhibits an opposite non-linearity with respect to temperature. The opposite non-linearity reduces the effect of the non-linearity on the output voltage of the bandgap voltage reference generator. The difference in gate-source voltages of the pair of MOSFETs may be determined by the ratio of channel width to channel length of each MOSFET included in the pair of MOSFETs.Type: ApplicationFiled: May 29, 2003Publication date: December 2, 2004Inventor: Thomas A. Somerville
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Patent number: 6747477Abstract: A programmable data latch (21) is disclosed. The data latch comprises a master latch (34) operable to load data into the data latch (21) and a slave latch (36) operable to receive the data and produce the output (20) and inverted output of the data latch (21). Also provided is a plurality of programmable floating gate transistor (53, 54) wherein the “on” or “off” state of the floating gate transistor (53, 54) is determined by the data loaded into the data latch (21). A programming voltage supply (26) is supplied to the floating gate transistors (53, 54) which increases the threshold voltage of the floating gate transistor (53, 54) in the “on” state and produces a programmed transistor. The programmed transistor is operable to set the state of the data latch (21) upon subsequent use.Type: GrantFiled: August 13, 2002Date of Patent: June 8, 2004Assignee: Semiconductor Components Industries, L.L.C.Inventors: Robert Maigret, Thomas Somerville
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Publication number: 20040032281Abstract: A programmable data latch (21) is disclosed. The data latch comprises a master latch (34) operable to load data into the data latch (21) and a slave latch (36) operable to receive the data and produce the output (20) and inverted output of the data latch (21). Also provided is a plurality of programmable floating gate transistor (53, 54) wherein the “on” or “off” state of the floating gate transistor (53, 54) is determined by the data loaded into the data latch (21). A programming voltage supply (26) is supplied to the floating gate transistors (53, 54) which increases the threshold voltage of the floating gate transistor (53, 54) in the “on” state and produces a programmed transistor. The programmed transistor is operable to set the state of the data latch (21) upon subsequent use.Type: ApplicationFiled: August 13, 2002Publication date: February 19, 2004Inventors: Robert Maigret, Thomas Somerville
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Publication number: 20040032293Abstract: An adjustable voltage reference circuit (14,25,70) that can be adjusted via an external device is disclosed. The circuit is designed to receive, after packaging, a plurality of adjustment inputs (20). These inputs are used by an adjustable voltage cell (21, 26, 71) to produce an adjustment factor. The adjustment factor will then be used by a voltage reference cell (22, 27, 72) to adjust the reference voltage (Vref).Type: ApplicationFiled: August 13, 2002Publication date: February 19, 2004Applicant: Semiconductor Components Industries, LLC.Inventors: Robert Maigret, Thomas Somerville
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Patent number: 6586987Abstract: A source follower output stage achieves low output impedance and high power supply rejection while operating at low output voltage and low supply voltage. This circuit has improved performance due to the source follower transistor, the sense transistor, and the output mirror, these items forming a common source difference amplifier. This common source difference amplifier adjusts the common voltage of the signal mirror to equalize the signal mirror input and output voltage. Thus, the common node of the mirror adapts to changing supply voltage, output load current and temperature so that the effect on source follower output voltage is minimized. Since the output node of the signal mirror is clamped to the source follower output instead of the common node of the mirror, the circuit operates at lower output and supply voltage than the prior art.Type: GrantFiled: June 14, 2001Date of Patent: July 1, 2003Assignees: Maxim Integrated Products, Inc., Standard Microsystems CorporationInventors: Thomas A Somerville, Praveen V. Nadimpalli
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Publication number: 20020190782Abstract: The present invention provides a circuit that includes a source follower transistor that is driven by a signal mirror, sense transistor, and an output mirror. This circuit has improved performance due to the source follower transistor, the sense transistor and the output mirror, these items forming a common source difference amplifier. This common source difference amplifier adjusts the common voltage of the signal mirror to equalize the signal mirror input and output voltage. Thus, the common node of the mirror where voltage may be measured adapts to changing supply voltage, output load current and temperature so that the effect on source follower output voltage is minimized. For optimum performance, the current density ratio of the output mirror devices is equal to the current density ratio of the sense transistor to the source follower transistor.Type: ApplicationFiled: June 14, 2001Publication date: December 19, 2002Inventors: Thomas A. Somerville, Praveen V. Nadimpalli
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Publication number: 20020130707Abstract: A voltage reference circuit (108) is disclosed. Voltage reference circuit (108) comprises an adjustable current source (202), a mirror circuit (302) and a bandgap circuit (206). The adjustable current source (204) outputs a current (I342) to the mirror circuit (302), which then mirrors the current to the bandgap circuit (206). If the load (110) of the voltage reference cell (108) requires a greater current, a feedback current (I3) is fed back to the adjustable current source (204) to increase its output current. The voltage reference circuit (108) of the present invention allows for a more efficient use of current.Type: ApplicationFiled: January 26, 2001Publication date: September 19, 2002Applicant: Semiconductor Components Industries, LLCInventors: Thomas A. Somerville, Bob Maigret
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Patent number: 6184750Abstract: The present invention teaches a variety of output stages for amplifying high speed signals while keeping distortion low and using a low supply voltage. The invention includes the use of dual complementary signal paths that include a complementary push-pull output stage. Bias circuits are used to keep the paths symmetrical and positive feedback is used to oppose output loading effects.Type: GrantFiled: May 27, 1999Date of Patent: February 6, 2001Assignee: Gain Technology, Inc.Inventor: Thomas A. Somerville
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Patent number: 6133764Abstract: A comparator circuit (10) with hysteresis having transistors with the same threshold voltage and a method for comparing input signals. The comparator circuit (10) includes a current mirror (11) coupled to a common electrode differential pair (12) and to a feedback circuit (13). The current mirror (11) has a large output impedance and provides a plurality of output currents (I.sub.21, I.sub.26, I.sub.31). Some (I.sub.21, I.sub.26) of the currents are transmitted to the common electrode differential pair and one (I.sub.31) of the currents is transmitted to the feedback circuit (13). The output currents (I.sub.21, I.sub.26, I.sub.31) are modulated to generate positive feedback signals that control changing the output state of the comparator circuit (10) as well as provide hysteresis for the comparator circuit (10).Type: GrantFiled: January 27, 1999Date of Patent: October 17, 2000Assignee: Motorola, Inc.Inventors: Richard S. Griffith, Robert L. Vyne, Thomas A. Somerville
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Patent number: 5900772Abstract: A bandgap reference circuit (60) provides a selectable bandgap reference voltage that is substantially insensitive to temperature variations of an operating reference circuit. A final curvature caused by a current (I.sub.2) in a temperature coefficient compensation transistor (40) is equal to a drift in a Vbe voltage of a transistor (18) having a negative temperature coefficient plus the drift in a Vbe voltage of a transistor (20) having a positive temperature coefficient minus the drift in a Vbe voltage of the temperature coefficient compensation transistor (40). The nonlinearity of the current (I.sub.2) in the temperature coefficient compensation transistor (40) is adjusted by selecting a compensating current and associated temperature coefficient for the compensating current (I.sub.0) to minimize the characteristic bow or curvature of the current (I.sub.2) in the temperature coefficient compensation transistor (40).Type: GrantFiled: March 18, 1997Date of Patent: May 4, 1999Assignee: Motorola, Inc.Inventors: Thomas A. Somerville, Robert L. Vyne
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Patent number: 5627494Abstract: A high side current sense amplifier (21) comprises a first resistor, a second resistor, an amplifier (22), and a darlington transistor pair. The first resistor has a first input and a second input coupled to a non-inverting input of the amplifier (22). The darlington transistor pair has a collector coupled to the non-inverting input of the amplifier (22), a base coupled to an output of amplifier (22), an emitter. The second resistor is coupled between the emitter of the darlington transistor pair and ground. A differential voltage is applied across the first input of the first resistor and an inverting input of the amplifier (22). The darlington transistor pair converts an output voltage of the amplifier (22) to a feedback current for generating a voltage across the first resistor. Under stable conditions the voltage across the first resistor is equal to the differential voltage. The voltage gain is the ratio of the second resistor to the first resistor.Type: GrantFiled: December 4, 1995Date of Patent: May 6, 1997Assignee: Motorola, Inc.Inventor: Thomas A. Somerville
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Patent number: 5598327Abstract: A planar transformer assembly includes an insulative layer, a first spiral winding thereon circumscribing a magnetic flux path, a second spiral winding thereon in non-overlapping relation to the first spiral winding circumscribing the magnetic flux path, and a ferrite core assembly including first and second core sections defining a shallow gap or passage within which the spiral windings are disposed. In one embodiment, a plurality of laminated insulative layers are provided with a primary winding including a plurality of series-connected spiral subwindings and a non-overlapping secondary winding formed on the various insulative layers. The non-overlapping structure and the order of the various windings minimize electric field gradients and thereby minimize electric field coupled noise currents.Type: GrantFiled: January 28, 1994Date of Patent: January 28, 1997Assignee: Burr-Brown CorporationInventors: Thomas A. Somerville, Walter B. Meinel, R. Mark Stitt, II