Patents by Inventor Thomas P. Bushey

Thomas P. Bushey 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: 6747494
    Abstract: A charge pump arrangement for a phase-locked-loop has a current source circuit (60) which provides charging current to the phase locked loop, and a current sink circuit (90) which depletes charging current from the phase locked loop. The current source circuit (60) and the current sink circuit (90) have slew rates which have a predetermined relationship. In this way, the charge pump causes substantially no non-linear charge injection in the phase-locked-loop. Cascoded current mirrors (75, 85) are utilised to provide a high voltage with thin gate oxide technology. The arrangement has a relatively small die size. Since bias currents of the arrangement are mirrored according to the output current required, improved transient times are produced, leading to reduced phase noise.
    Type: Grant
    Filed: February 15, 2002
    Date of Patent: June 8, 2004
    Assignee: Motorola, Inc.
    Inventors: Thomas P. Bushey, Jeremy W Moore, Morgan Fitzgibbon
  • Publication number: 20030155951
    Abstract: A charge pump arrangement for a phase-locked-loop has a current source circuit (60) which provides charging current to the phase locked loop, and a current sink circuit (90) which depletes charging current from the phase locked loop. The current source circuit (60) and the current sink circuit (90) have slew rates which have a predetermined relationship. In this way, the charge pump causes substantially no non-linear charge injection in the phase-locked-loop. Cascoded current mirrors (75, 85) are utilised to provide a high voltage with thin gate oxide technology. The arrangement has a relatively small die size. Since bias currents of the arrangement are mirrored according to the output current required, improved transient times are produced, leading to reduced phase noise.
    Type: Application
    Filed: February 15, 2002
    Publication date: August 21, 2003
    Inventors: Thomas P. Bushey, Jeremy W. Moore, Morgan Fitzgibbon
  • Patent number: 6026003
    Abstract: A charge pump (102) and method of charge pumping a low voltage (V.sub.DD)) to generate a higher voltage (V.sub.PP). A primary pump (160, 179, 180) receives complementary clock signals (CLK1, CLK2) that control charging and transfer cycles of the charge pump. During the charging cycle, a capacitor (150) stores a charge developed from the low voltage. On the transfer cycle, the charge is transferred to an output (138, 177, 178) through a switching transistor (152) disposed in a well region (202) to develop the higher voltage. A secondary pump (162, 187, 188) charge pumps the output voltage to generate a more positive bias voltage for biasing the well region to disable a parasitic PNP transistor of the switching transistor.
    Type: Grant
    Filed: December 18, 1998
    Date of Patent: February 15, 2000
    Assignee: Motorola, Inc.
    Inventors: Jeremy W. Moore, James S. Caravella, Thomas P. Bushey
  • Patent number: 5898617
    Abstract: A circuit (28) and method of sensing data stored in a memory circuit provide a reference current (I.sub.REF) that tracks memory cell current (I.sub.BIT) over a range of temperatures and power supply voltages. A comparator circuit (66) senses the memory cell current with respect to the reference current to produce the stored data (V.sub.DATA) By sensing current rather than voltage, the voltage swing on a high capacitance bitline (39) can be reduced to improve speed. The reference current is set during testing of the circuit by applying programming voltages (V.sub.WELL, V.sub.CG, V.sub.BL) to a reference device (52) that matches a storage device (36) in the memory cell (30).
    Type: Grant
    Filed: May 21, 1997
    Date of Patent: April 27, 1999
    Assignee: Motorola, Inc.
    Inventors: Thomas P. Bushey, James S. Caravella, David F. Mietus
  • Patent number: 5828607
    Abstract: A circuit and method modify data stored in a storage element (30) of a memory circuit (110) when high voltages used for such modification exceed transistor breakdowns. A charge pump (302) produces a pumped voltage (V.sub.P1) for modifying the data. A monitor circuit (304) produces an enable signal (V.sub.PEN) to activate other power supply voltages when the pumped voltage reaches a predetermined voltage level for allowing the data to be modified. A routing circuit (832) selects between the pumped voltage and a first voltage (V.sub.DD) in response to a first control signal (HVENABLEP) to produce a selected voltage. A switching circuit (802-808) passes the selected voltage to the storage element (30) to modify the data when the first supply voltage is selected by the routing circuit.
    Type: Grant
    Filed: May 21, 1997
    Date of Patent: October 27, 1998
    Assignee: Motorola, Inc.
    Inventors: Thomas P. Bushey, James S. Caravella, Jeremy W. Moore
  • Patent number: 5117391
    Abstract: A bipolar memory array arranged in a row and column matrix is responsive to a plurality of word line driver transistors for selecting one row of memory cells thereof. The current flowing through each memory cell is provided by a pair or lateral PNP transistor current source loads. The collectors of the word line driver transistors are commonly connected for distributing the source of collector current flowing therethrough between the bases of all of the laterla PNP transistor current sources of the entire memory array which maintains a constant current flow through each of the memory cells during the select and deselect cycles thereby maintaining a constant memory cell array power dissipation which allows for expanded capacity of the memory array and a performance improvement.
    Type: Grant
    Filed: June 4, 1990
    Date of Patent: May 26, 1992
    Assignee: Motorola, Inc.
    Inventors: Bor-Yuan Hwang, Thomas P. Bushey
  • Patent number: 4871928
    Abstract: A BICMOS inverter circuit having a high input impedance, improved switching characteristics, low power requirements, high noise immunity, high drive capability, an increased output voltage swing, reduced body effect, high current drivability and improved power dissipation comprises a CMOS inverter for receiving an input signal and bipolar push-pull output transistors for supplying an output. An intermediate CMOS stage is coupled between the CMOS inverter and the bipolar push-pull output transistors and to power supply voltages in a manner that eliminates body effect.
    Type: Grant
    Filed: August 23, 1988
    Date of Patent: October 3, 1989
    Assignee: Motorola Inc.
    Inventor: Thomas P. Bushey
  • Patent number: 4857479
    Abstract: Improved semiconductor devices having minimum parasitic junction area are formed by using multiple buried polycrystalline conductor layers to make lateral contact to one or more pillar-shaped epitaxial single crystal device regions. The lateral poly contacts are isolated from each other and from the substrate and have at least one polycrystalline pillar extending to upper surface of the device to permit external connections to the lowest poly layer. The lateral epi-poly sidewall contacts are recessed under the intervening oxide layers to separate them from the active device regions in the center of the epi pillar.The structure is made by depositing three dielectric layers with two poly layers sandwiched in between. Holes are anisotropically etched to the lowest poly layer and the substrate. The exposed edges of the poly layers are oxidized. These edge oxide regions are removed in the holes where the device pillars are epitaxially grown.
    Type: Grant
    Filed: May 9, 1988
    Date of Patent: August 15, 1989
    Assignee: Motorola
    Inventors: Kevin L. McLaughlin, Thomas P. Bushey
  • Patent number: 4810903
    Abstract: A BICMOS driver circuit is provided having high input impedence and high output current drive with low static power dissipation that provides supply voltages and full logic output voltage swing for circuits having submicron dimensions. An inverter circuit is coupled to a voltage divider circuit and the input terminal for inverting the input signal. A complementary emitter follower circuit is coupled to an output terminal for providing a digital output signal. A current source circuit is coupled to the complementary emitter follower circuit and the input terminal for sourcing current to the complementary emitter follower circuit in response to the input signal. A bipolar bias circuit is coupled to the complementary emitter follower circuit and the inverter circuit for biasing the complementary emitter follower circuit in response to an inverted input signal.
    Type: Grant
    Filed: December 14, 1987
    Date of Patent: March 7, 1989
    Assignee: Motorola, Inc.
    Inventors: Thomas P. Bushey, Walter C. Seelbach
  • Patent number: 4806796
    Abstract: An active load for a CML or ECL logic gate for substantially increasing the speed of the gate comprises a transistor having its base coupled to its collector by a first resistor, and its collector-emitter path coupled in series with a second resistor. This load provides an inductive impedance when the small signal emitter resistance is less than the sum of the resistance of the base and the first resistor, causing a peaking effect resulting in high switching speed.
    Type: Grant
    Filed: March 28, 1988
    Date of Patent: February 21, 1989
    Assignee: Motorola, Inc.
    Inventors: Thomas P. Bushey, Bor-Yuan Hwang
  • Patent number: 4764801
    Abstract: Improved semiconductor devices having minimum parasitic junction area are formed by using multiple buried polycrystalline conductor layers to make lateral contact to one or more pillar-shaped epitaxial single crystal device regions. The lateral poly contacts are isolated from each other and from the substrate and have at least one polycrystalline pillar extending to upper surface of the device to permit external connections to the lowest poly layer. The lateral epi-poly sidewall contacts are recessed under the intervening oxide layers to separate them from the active device regions in the center of the epi pillar. The structure is made by depositing three dielectric layers with two poly layers sandwiched in between. Holes are anisotropically etched to the lowest poly layer and the substrate. The exposed edges of the poly layers are oxidized. These edge oxide regions are removed in the holes where the device pillars are epitaxially grown.
    Type: Grant
    Filed: June 3, 1987
    Date of Patent: August 16, 1988
    Assignee: Motorola Inc.
    Inventors: Kevin L. McLaughlin, Thomas P. Bushey
  • Patent number: 4696097
    Abstract: Improved semiconductor devices having minimum parasitic junction area are formed by using multiple buried polycrystalline conductor layers to make lateral contact to one or more pillar-shaped epitaxial single crystal device regions. The lateral poly contacts are isolated from each other and from the substrate and have at least one polycrystalline pillar extending to upper surface of the device to permit external connections to the lower poly layer.The structure is made by depositing three dielectric layers with two poly layers sandwiched in between. Holes are anisotropically etched to the lowest poly layer and the substrate. A conformal oxide is applied over the whole structure and anisotropically etched to remove the bottom portions in the hole where the poly pillar and the isolation wall are to be formed and isotropically where the single crystal pillar is to be formed. The remaining oxide regions isolate the buried conductor layers, contacts, and isolation walls.
    Type: Grant
    Filed: October 8, 1985
    Date of Patent: September 29, 1987
    Assignee: Motorola, Inc.
    Inventors: Kevin L. McLaughlin, Thomas P. Bushey