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).

  • Patent number: 9793861
    Abstract: 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: Grant
    Filed: July 28, 2016
    Date of Patent: October 17, 2017
    Assignee: QUALCOMM Incorporated
    Inventor: Thomas Somerville
  • Patent number: 9092041
    Abstract: 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: Grant
    Filed: July 27, 2012
    Date of Patent: July 28, 2015
    Assignee: Maxim Integrated Products, Inc.
    Inventor: Thomas A. Somerville
  • Patent number: 7557551
    Abstract: 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: Grant
    Filed: July 14, 2006
    Date of Patent: July 7, 2009
    Assignee: RF Micro Devices, Inc.
    Inventors: Thomas A. Somerville, Michael R. Kay, David C. Dening
  • Patent number: 7535204
    Abstract: 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: Grant
    Filed: March 9, 2007
    Date of Patent: May 19, 2009
    Assignee: RF Micro Devices, Inc.
    Inventors: Praveen V. Nadimpalli, Thomas A. Somerville
  • Patent number: 6876249
    Abstract: 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: Grant
    Filed: August 13, 2002
    Date of Patent: April 5, 2005
    Assignee: Semiconductor Components Industries, LLC
    Inventors: Robert Maigret, Thomas Somerville
  • Patent number: 6856189
    Abstract: 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: Grant
    Filed: May 29, 2003
    Date of Patent: February 15, 2005
    Assignee: Standard Microsystems Corporation
    Inventor: Thomas A. Somerville
  • Publication number: 20050012554
    Abstract: 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: Application
    Filed: July 17, 2003
    Publication date: January 20, 2005
    Inventors: Thomas Somerville, Klaas Wortel
  • Patent number: 6838942
    Abstract: 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: Grant
    Filed: July 17, 2003
    Date of Patent: January 4, 2005
    Assignee: Standard Microsystems Corporation
    Inventors: Thomas A. Somerville, Klaas Wortel
  • Publication number: 20040239411
    Abstract: 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: Application
    Filed: May 29, 2003
    Publication date: December 2, 2004
    Inventor: Thomas A. Somerville
  • Patent number: 6747477
    Abstract: 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: Grant
    Filed: August 13, 2002
    Date of Patent: June 8, 2004
    Assignee: Semiconductor Components Industries, L.L.C.
    Inventors: Robert Maigret, Thomas Somerville
  • Publication number: 20040032281
    Abstract: 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: Application
    Filed: August 13, 2002
    Publication date: February 19, 2004
    Inventors: Robert Maigret, Thomas Somerville
  • Publication number: 20040032293
    Abstract: 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: Application
    Filed: August 13, 2002
    Publication date: February 19, 2004
    Applicant: Semiconductor Components Industries, LLC.
    Inventors: Robert Maigret, Thomas Somerville
  • Patent number: 6586987
    Abstract: 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: Grant
    Filed: June 14, 2001
    Date of Patent: July 1, 2003
    Assignees: Maxim Integrated Products, Inc., Standard Microsystems Corporation
    Inventors: Thomas A Somerville, Praveen V. Nadimpalli
  • Publication number: 20020190782
    Abstract: 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: Application
    Filed: June 14, 2001
    Publication date: December 19, 2002
    Inventors: Thomas A. Somerville, Praveen V. Nadimpalli
  • Publication number: 20020130707
    Abstract: 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: Application
    Filed: January 26, 2001
    Publication date: September 19, 2002
    Applicant: Semiconductor Components Industries, LLC
    Inventors: Thomas A. Somerville, Bob Maigret
  • Patent number: 6184750
    Abstract: 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: Grant
    Filed: May 27, 1999
    Date of Patent: February 6, 2001
    Assignee: Gain Technology, Inc.
    Inventor: Thomas A. Somerville
  • Patent number: 6133764
    Abstract: 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: Grant
    Filed: January 27, 1999
    Date of Patent: October 17, 2000
    Assignee: Motorola, Inc.
    Inventors: Richard S. Griffith, Robert L. Vyne, Thomas A. Somerville
  • Patent number: 5900772
    Abstract: 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: Grant
    Filed: March 18, 1997
    Date of Patent: May 4, 1999
    Assignee: Motorola, Inc.
    Inventors: Thomas A. Somerville, Robert L. Vyne
  • Patent number: 5627494
    Abstract: 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: Grant
    Filed: December 4, 1995
    Date of Patent: May 6, 1997
    Assignee: Motorola, Inc.
    Inventor: Thomas A. Somerville
  • Patent number: 5598327
    Abstract: 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: Grant
    Filed: January 28, 1994
    Date of Patent: January 28, 1997
    Assignee: Burr-Brown Corporation
    Inventors: Thomas A. Somerville, Walter B. Meinel, R. Mark Stitt, II