Patents by Inventor Carver A. Mead

Carver A. Mead 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: 5204549
    Abstract: A weight-storage and weight-adjustment circuit includes a first hot electron injection device coupled to a first floating gate and a second hot electron injection device coupled to the second floating gate. The floating gates are associated with two series connected MOS transistors. The first and second hot electron injection devices comprise gated lateral bipolar transistors. The weight may be decreased by injecting hot electrons from the first hot electron injection device onto the first floating gate to decrease the first analog voltage and increased by injecting electrons from the second hot electron injection device onto the second floating gate to decrease the second analog voltage. Circuitry are provided to periodically adjust the absolute voltage levels on the first and second floating gates to prevent them from becoming too negative over time.
    Type: Grant
    Filed: January 28, 1992
    Date of Patent: April 20, 1993
    Assignee: Synaptics, Incorporated
    Inventors: John C. Platt, Janeen D. W. Anderson, Carver A. Mead
  • Patent number: 5166562
    Abstract: A circuit for generating N analog voltage signals for reference or bias use employs N analog floating gate storage devices. Electron injection circuitry is provided for injecting electrons on to and a tunneling structure is provided for removing electrons from the floating gate of each floating gate storage device. A follower amplifier is connected to each floating gate storage device and drives an analog output voltage bus. A capacitor is connected to each analog output storage bus. An analog pass gate is connected between each analog output voltage bus and a common monitor/dynamic load bus. Each analog pass gate is driven by a strobe signal.
    Type: Grant
    Filed: May 9, 1991
    Date of Patent: November 24, 1992
    Assignee: Synaptics, Incorporated
    Inventors: Timothy P. Allen, Adam K. Greenblatt, Carver A. Mead, Janeen D. W. Anderson
  • Patent number: 5165054
    Abstract: A linear voltage-to-current converter (LVCC) circuit includes two transistors, one P-channel and one N-channel. The input voltage is applied to the gates of both transistors. The drains of the two transistors are connected. The source of the p-type transistor is connected to a first voltage rail, and the source of the N-channel is connected to a second voltage rail of lower voltage. The output is the difference between the current through the P-channel transistor and the N-channel transistor. A linear current-to-voltage converter (LCVC) circuit is similar to the LVCC circuit, except that the gates of the transistors are tied to the drains of the transistors. The input current is supplied to the drains, and the output voltage is the voltage of the drains.
    Type: Grant
    Filed: December 18, 1990
    Date of Patent: November 17, 1992
    Assignee: Synaptics, Incorporated
    Inventors: John C. Platt, Michael F. Wall, Glenn E. Gribble, Carver A. Mead
  • Patent number: 5160899
    Abstract: An adaptable current mirror includes first and second MOS transistors. The first MOS transistor has its gate connected to its drain. A MOS capacitor structure is connected in series between the gate of the first MOS transistor and the gate of the second MOS transistor. Electrons may be placed onto and removed in an analog manner from a floating node associated with the second MOS transistor, usually the gate of the transistor, by application of first and second electrical control signals. A first electrical control signal controls the injection of electrons onto the floating node from an electron injection structure and the second electrical control signal controls the removal of electrons from the floating node by an electron removal structure. A plurality of adaptable current mirrors communicating with a plurality of current-carrying lines may be employed for indicating the output of the one of the plurality of current-carrying lines through which the most current is flowing.
    Type: Grant
    Filed: October 22, 1991
    Date of Patent: November 3, 1992
    Assignee: Synaptics, Incorporated
    Inventors: Janeen D. W. Anderson, Carver A. Mead, Timothy P. Allen, Michael F. Wall
  • Patent number: 5146106
    Abstract: An adaptable MOS winner take all circuit includes a plurality of adaptable current mirrors. Each adaptable current mirror includes a floating node onto which and from which electrons may be transported by control signals and electrical semiconductor structures. Electrons may be placed onto and removed from a floating node associated with at least one MOS insulated gate field effect transistor, usually the gate of the transistor, in an analog manner, by application of first and second electrical control signals. A first electrical control signal controls the injection of electrons onto the floating node from an electron injection structure and the second electrical control signal controls the removal of electrons from the floating node by an electron removal structure.
    Type: Grant
    Filed: February 5, 1991
    Date of Patent: September 8, 1992
    Assignee: Synaptics, Incorporated
    Inventors: Janeen D. W. Anderson, Carver A. Mead, Timothy P. Allen, Michael F. Wall
  • Patent number: 5126685
    Abstract: A linear voltage-to-current converter (LVCC) circuit includes two transistors, one P-channel and one N-channel. The input voltage is applied to the gates of both transistors. The drains of the two transistors are connected. The source of the p-type transistor is connected to a first voltage rail, and the source of the N-channel is connected to a second voltage rail of lower voltage. The output is the difference between the current through the P-channel transistor and the N-channel transistor. A linear current-to-voltage converter (LCVC) circuit is similar to the LVCC circuit, except that the gates of the transistors are tied to the drains of the transistors. The input current is supplied to the drains, and the output voltage is the voltage of the drains.
    Type: Grant
    Filed: August 19, 1991
    Date of Patent: June 30, 1992
    Assignee: Synaptics, Incorporated
    Inventors: John C. Platt, Michael F. Wall, Glenn E. Gribble, Carver A. Mead
  • Patent number: 5120996
    Abstract: An electronic circuit is disclosed having a sample/hold amplifier connected to an adaptive amplifier. A plurality of such electronic cicuits may be configured in an array of rows and columns. An input voltage vector may be compared with an analog voltage vector stored in a row or column of the array and the stored vector closest to the applied input vector may be identified and further processed.
    Type: Grant
    Filed: June 6, 1990
    Date of Patent: June 9, 1992
    Assignee: Synaptics, Incorporated
    Inventors: Carver A. Mead, Federico Faggin, Timothy P. Allen, Janeen D. W. Anderson
  • Patent number: 5119038
    Abstract: An MOS current mirror includes a floating node onto which and from which electrons may be transported by control signals and electrical semiconductor structures in order to adapt the current mirror to supply a desired output current when a particular input calibration current is present.
    Type: Grant
    Filed: February 4, 1991
    Date of Patent: June 2, 1992
    Assignee: Synaptics, Corporation
    Inventors: Janeen D. W. Anderson, Carver A. Mead, Timothy P. Allen, Michael F. Wall
  • Patent number: 5109261
    Abstract: An integrated circuit amplifier having a random input offset voltage is adaptable such that the input offset voltage may be cancelled out. An inverting input node is a floating input node and is coupled to a source of input signal by a first capacitor. A second capacitor is connected between the output of the amplifier and the floating node. An ultraviolet window above the second capacitor allows the floating node to be charged, by the application of ultraviolet light, to a voltage which effectively cancels the input offset voltage. The ultraviolet window and capacitor electrodes are arranged such that the ultraviolet light may strike only the desired areas of the structure.
    Type: Grant
    Filed: October 31, 1990
    Date of Patent: April 28, 1992
    Assignee: Synaptics, Incorporated
    Inventors: Carver A. Mead, Timothy P. Allen
  • Patent number: 5107149
    Abstract: A linear voltage-to-current converter (LVCC) circuit includes two transistors, one P-channel and one N-channel. The input voltage is applied to the gates of both transistors. The drains of the two transistors are connected. The source of the p-type transistor is connected to a first voltage rail, and the source of the N-channel is connected to a second voltage rail of lower voltage. The output is the difference between the current through the P-channel transistor and the N-channel transistor. A linear current-to-voltage converter (LCVC) circuit is similar to the LVCC circuit, except that the gates of the transistors are tied to the drains of the transistors. The input current is supplied to the drains, and the output voltage is the voltage of the drains.
    Type: Grant
    Filed: August 19, 1991
    Date of Patent: April 21, 1992
    Assignee: Synaptics, Inc.
    Inventors: John C. Platt, Michael F. Wall, Glenn E. Gribble, Carver A. Mead
  • Patent number: 5103116
    Abstract: A CMOS single phase register includes two pairs of cross coupled CMOS inverters connected together by transistor switches. The first pair of cross-coupled CMOS inverters is connected to a complementary pair of data inputs through a first pair of transistor switches which turn on in response to a first logic level. The complementary outputs of the first pair of cross-coupled CMOS inverters is connected to the inputs of the second pair of cross-coupled CMOS inverters through a second pair of transistor switches which turn on in response to a second logic level. The complementary outputs of the CMOS single phase register of the present invention are the outputs of the second pair of cross-coupled CMOS inverters. The ground connections of the first pair of cross-coupled CMOS inverters is made through a transistor switch which turns on in response to the first logic level.
    Type: Grant
    Filed: April 15, 1991
    Date of Patent: April 7, 1992
    Assignee: California Institute of Technology
    Inventors: Massimo Sivilotti, Carver A. Mead
  • Patent number: 5099156
    Abstract: A first and a second MOS transistor of the same conductivity type are connected in series between a load and a fixed voltage source. The gates of the first and second MOS transistors are connected to sources of input voltage which are of a magnitude smaller than the threshold voltages of the two MOS transistors. The first MOS transistor located next to the load is kept in saturation. A related circuit includes a first and a second MOS transistor of the same conductivity type are connected in series between a load and a fixed voltage source. The first MOS transistor located next to the load is kept in saturation. The gates of the first and second MOS transistors are connected to the gates of third and fourth diode-connected MOS transistors of the same conductivity type as the first and second MOS transistors. The third MOS transistor is connected between a first input current node and fixed voltage source. The fourth MOS transistor is connected between a second input current node and a fixed voltage source.
    Type: Grant
    Filed: October 2, 1990
    Date of Patent: March 24, 1992
    Assignee: California Institute of Technology
    Inventors: Tobias Delbruck, Carver A. Mead
  • Patent number: 5097305
    Abstract: An integrating photosensor includes an NPN phototransistor having its collector connected to a source of positive voltage, a P-channel MOS transistor having its gate connected to row-select line, its source connected to the emitter of the phototransistor, and its drain connected to a column sense line. The NPN phototransistor has an intrinsic base-collector capacitance. An integrating sense amplifier according to the present invention includes an amplifying element having an inverting input and a non-inverting input. The non-inverting input is connected to a source of reference voltage the inverting input is connected to a sense line. A P-channel balance transistor is connected between the inverting input and the output of the amplifying element and a capacitor is also connected between the inverting input and output of the amplifying element. An exponential feedback element is connected between the output and the inverting input of the amplifying element.
    Type: Grant
    Filed: February 19, 1991
    Date of Patent: March 17, 1992
    Assignee: Synaptics Corporation
    Inventors: Carver A. Mead, Federico Faggin
  • Patent number: 5095284
    Abstract: A first linear voltage to current converter includes an MOS current source transistor with its gate connected to a source of fixed voltage, used to feed the source of an MOS follower transistor. A second linear voltage to current converter includes a bipolar current source transistor with its base connected to a source of fixed voltage, used to feed the source of an MOS follower transistor. A differential pair includes in each leg a bipolar current source transistor with its base connected to a source of fixed voltage feeding the source of an MOS follower transistor. A differential amplifer includes two circuit legs including these transistor circuits.
    Type: Grant
    Filed: September 10, 1990
    Date of Patent: March 10, 1992
    Assignee: Synaptics, Incorporated
    Inventor: Carver A. Mead
  • Patent number: 5083044
    Abstract: An electronic circuit is disclosed having a sample/hold amplifier connected to an adaptive amplifier. A plurality of such electronic circuits may be configured in an array of rows and columns. An input voltage vector may be compared with an analog voltage vector stored in a row or column of the array and the stored vector closest to the applied input vector may be identified and further processed.
    Type: Grant
    Filed: May 25, 1989
    Date of Patent: January 21, 1992
    Assignee: Synaptics, Incorporated
    Inventors: Carver A. Mead, Timothy P. Allen, Federico Faggin, Janeen D. W. Anderson
  • Patent number: 5073759
    Abstract: An integrated circuit amplifier having a random input offset voltage is adaptable such that then input offset voltage may be cancelled out. An inverting input node is a floating input node and is coupled to a source of input signal by a first capacitor. A second capacitor is connected between the output of the amplifier and the floating node. An ultraviolet window above the second capacitor allows the floating node to be charged, by the application of ultraviolet light, to a voltage which effectively cancels the input offset voltage. The ultraviolet window and capacitor electrodes are arranged such that the ultraviolet light may strike only the desired areas of the structure.
    Type: Grant
    Filed: October 31, 1990
    Date of Patent: December 17, 1991
    Assignee: Synaptics, Incorporated
    Inventors: Carver A. Mead, Timothy P. Allen
  • Patent number: 5068622
    Abstract: An integrated circuit amplifier having a random input offset voltage is adaptable such that the input offset voltage may be cancelled out. An inverting input node is a floating input node and is coupled to a source of input signal by a first capacitor. A second capacitor is connected between the output of the amplifier and the floating node. An ultraviolet window above the second capacitor allows the floating node to be charged, by the application of ultraviolet light, to a voltage which effectively cancels the input offset voltage. The ultraviolet window and capacitor electrodes are arranged such that the ultraviolet light may strike only the desired areas of the structure.
    Type: Grant
    Filed: February 28, 1990
    Date of Patent: November 26, 1991
    Assignee: Synaptics, Incorporated
    Inventors: Carver A. Mead, Timothy P. Allen
  • Patent number: 5059920
    Abstract: Electrons may be placed onto and removed from a floating node associated with at least one MOS transistor, usually the gate of the transistor, in an analog manner, by application of first and second electrical control signals. A first electrical control signal controls the injection of electrons onto the floating node from an electron injection structure and the second electrical control signal controls the removal of electrons from the floating node by an electron removal structure.An analog MOS integrated circuit comprises an amplifier circuit having a gain much larger than 1. The inverting input into one stage of this amplifier circuit is a floating node forming the gate of at least one MOS transistor. A first capacitor couples an input of the circuit to this floating node. Electrical semiconductor structures are provided for both linearly adding and removing charge from the floating gate, thus allowing the offset voltage of the amplifier to be adapted.
    Type: Grant
    Filed: May 18, 1990
    Date of Patent: October 22, 1991
    Assignee: Synaptics, Incorporated
    Inventors: Janeen D. W. Anderson, Carver A. Mead, Timothy P. Allen, Michael F. Wall
  • Patent number: 5059814
    Abstract: A CMOS analog integrated circuit comprising a plurality of nodes for simultaneously computing the largest of the signals at inputs of the nodes. There is a common line supplying current and producing a maximum voltage potential and a plurality of nodes connected to the common line. Each node comprises a follower transistor having a source operably connected to the common line for sourcing current and a gate being the input of the node and being connected to a current signal input source providing a current signal to the node to be compared to the current signals at respective ones of the other nodes. There is an inhibitor transistor having a gate connected to the common line and a drain operably connected to the gate of the follower transistor. The inhibitor transistor provides the voltage output of the node and inhibits the voltage output at all nodes connected to the common line which have a current signal which is smaller than the largest current signal connected to one of the nodes.
    Type: Grant
    Filed: November 30, 1988
    Date of Patent: October 22, 1991
    Assignee: The California Institute of Technology
    Inventors: Carver A. Mead, John Lazzaro, M. A. Mahowald, Sylvie Ryckebusch
  • Patent number: 5049758
    Abstract: An integrated circuit amplifier having a random input offset voltage is adaptable such that the input offset voltage may be cancelled out. An inverting input node is a floating input node and is coupled to a source of input signal by a first capacitor. A second capacitor is connected between the output of the amplifier and the floating node. An ultraviolet window above the second capacitor allows the floating node to be charged, by the application of ultraviolet light, to a voltage which effectively cancels the input offset voltage. The ultraviolet window and capacitor electrodes are arranged such that the ultraviolet light may strike only the desired areas of the structure.
    Type: Grant
    Filed: October 31, 1990
    Date of Patent: September 17, 1991
    Assignee: Synaptics, Incorporated
    Inventors: Carver A. Mead, Timothy P. Allen