Patents by Inventor John A. Fifield
John A. Fifield 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: 20050156666Abstract: A low-voltage differential amplifier circuit is disclosed. The low-voltage differential amplifier circuit includes a first differential amplifier, a second differential amplifier and a summing circuit. The first differential amplifier receives a pair of differential input signals to generate a first output. The second differential amplifier receives the same pair of differential input signals to generate a second output. The summing circuit sums the first output of the first differential amplifier and the second output of the second differential amplifier to provide a common output.Type: ApplicationFiled: January 21, 2004Publication date: July 21, 2005Applicant: INTERNATIONAL BUSINESS MACHINES CORPORATIONInventors: John Fifield, Steven Lamphier
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Patent number: 6917319Abstract: A method and structure for a digital-to-analog converter comprising a voltage source supply; a voltage division stack connected to the voltage source supply; a multiplexer connected to the voltage division stack; a digital circuit connected to the multiplexer; an analog circuit connected to the multiplexer; and an input binary word source connected to the digital circuit, wherein outputs of the digital circuit are input into the analog circuit and converted as analog output. According to the invention, the multiplexer comprises any of an NFET and/or a PFET. The digital-to-analog converter further comprises a capacitor connected to the analog circuit and a binary-weighted tunneling current device connected to the digital circuit. The multiplexer and the capacitor are made of thick oxide (at least 5 nm thick). The tunneling current device outputs tunneling current, wherein the tunneling current is adjusted in proportion to a binary weight of the input binary word source.Type: GrantFiled: March 30, 2004Date of Patent: July 12, 2005Assignee: International Business Machines CorporationInventors: Wagdi W. Abadeer, John A. Fifield
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Patent number: 6912665Abstract: A test methodology is used to conduct an automatic chip timing analysis in coarse and fine resolution steps. Timing adjustment circuits implement coarse timing adjustment and fine timing adjustment for chip timing analysis. Timings such as clock, address and control inputs to a memory system can be digitally adjusted with respect to each other. A timer circuit is provided with a counter so that an incremental or decremental timing analysis can be carried out with a specific timing step. An algorithm is implemented which provides an effective, low-cost and accurate timing analysis. A nested loop is set up in the BIST where all possibilities of timing relationships between two or more signals can be applied to a device under test, and weaknesses, or failing timing conditions, can be found.Type: GrantFiled: April 5, 2001Date of Patent: June 28, 2005Assignee: International Business Machines CorporationInventors: Wayne F. Ellis, John A. Fifield, Louis Hsu, William V. Huott
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Publication number: 20050133884Abstract: An antifuse device (120) that includes a bias element (124) and an programmable antifuse element (128) arranged in series with one another so as to form a voltage divider having an output node (F) located between the bias and antifuse elements. When the antifuse device is in its unprogrammed state, each of the bias element and antifuse element is non-conductive. When the antifuse device is in its programmed state, the bias element remains non-conductive, but the antifuse element is conductive. The difference in the resistance of the antifuse element between its unprogrammed state and programmed state causes the difference in voltages seen at the output node to be on the order of hundreds of mili-volts when a voltage of 1 V is applied across the antifuse device. This voltage difference is so high that it can be readily sensed using a simple sensing circuit (228).Type: ApplicationFiled: February 4, 2005Publication date: June 23, 2005Applicant: International Business Machines CorporationInventors: John Fifield, Wagdi Abadeer, William Tonti
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Publication number: 20050122160Abstract: A method and circuit for tunneling leakage current compensation, the method including: forcing a current of known value through a tunneling current leakage monitor device to provide a voltage signal; and regulating an on-chip power supply of the integrated circuit chip based on the voltage signal.Type: ApplicationFiled: December 9, 2003Publication date: June 9, 2005Applicant: International Business Machines CorporationInventors: Wagdi Abadeer, Jennifer Appleyard, John Fifield, William Tonti
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Publication number: 20050110535Abstract: A circuit, including: a capacitor coupled between a first circuit node and a second circuit node and that leaks a leakage current from the first circuit node to the second circuit node; and a compensation circuit adapted to supply a compensatory current to compensate for the leakage current to the first circuit node.Type: ApplicationFiled: November 21, 2003Publication date: May 26, 2005Applicant: INTERNATIONAL BUSINESS MACHINES CORPORATIONInventors: Kerry Bernstein, Anthony Bonaccio, John Fifield, Allen Haar, Shiu Ho, Terence Hook, Michael Sorna, Stephen Wyatt
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Patent number: 6879638Abstract: A method and system for providing communication between electronic devices that uses the phase of data transmitted between the devices to indicate logical one and zero values. The method and system has the added benefit of relieving the traditional limitations of voltage communication restraints between devices having differing core voltages (i.e. Differing generations).Type: GrantFiled: December 28, 1999Date of Patent: April 12, 2005Assignee: International Business Machines CorporationInventors: Claude L. Bertin, Anthony R. Bonaccio, John A. Fifield, Wilbur D. Pricer, William R. Tonti
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Publication number: 20050073354Abstract: A voltage divider for integrated circuits that does not include the use of resistors. In one embodiment, voltage node VDD is connected with two n-type transistors, NFET1 and NFET2, which are connected in series. NFET 1 includes a source (12), a drain (14), a gate electrode (16) having a gate area A1 (not shown), and a p-substrate (18). NFET2 includes a source (20), a drain (22), a gate electrode (24) having a gate area A2 (not shown), and a p-substrate (26). Source (12) and drain (14) of NFET1 are coupled with gate electrode (24) of NFET2. The voltage difference between NFET1 and NFET2 has a linear function with VDD. As a result, voltage VDD may be divided between NFET1 and NFET2 by properly choosing the ratio between each of the respective transistor gate electrode areas, (A1) and (A2).Type: ApplicationFiled: October 1, 2003Publication date: April 7, 2005Applicant: INTERNATIONAL BUSINESS MACHINES CORPORATIONInventors: Wagdi Abadeer, John Fifield, William Tonti
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Publication number: 20050073023Abstract: An antifuse device (120) that includes a bias element (124) and an programmable antifuse element (128) arranged in series with one another so as to form a voltage divider having an output node (F) located between the bias and antifuse elements. When the antifuse device is in its unprogrammed state, each of the bias element and antifuse element is non-conductive. When the antifuse device is in its programmed state, the bias element remains non-conductive, but the antifuse element is conductive. The difference in the resistance of the antifuse element between its unprogrammed state and programmed state causes the difference in voltages seen at the output node to be on the order of hundreds of mili-volts when a voltage of 1 V is applied across the antifuse device. This voltage difference is so high that it can be readily sensed using a simple sensing circuit (228).Type: ApplicationFiled: October 6, 2003Publication date: April 7, 2005Applicant: INTERNATIONAL BUSINESS MACHINES CORPORATIONInventors: John Fifield, Wagdi Abadeer, William Tonti
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Publication number: 20050012045Abstract: A detector circuit and method for detecting a silicon well voltage or current to indicate an alpha particle or cosmic ray strike of the silicon well. One significant application for the detection circuit of the present invention is for the redundancy repair latches that are used in SRAMs. The redundancy repair latches are normally written once at power-up to record failed latch data and are not normally written again. If one of the latches changes states due to an SER (Soft Error Rate-such as a strike by an alpha particle or cosmic ray) event, the repair data in the redundancy latches of the SRAM would now be incorrectly mapped. The detector circuit and method monitors the latches for the occurrence of an SER event, and responsive thereto issues a reload of the repair data to the redundancy repair latches.Type: ApplicationFiled: July 18, 2003Publication date: January 20, 2005Applicant: INTERNATIONAL BUSINESS MACHINES CORPORATIONInventors: John Fifield, Paul Kartschoke, William KIaasen, Stephen Kosonocky, Randy Mann, Jeffery Oppold, Norman Rohrer
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Publication number: 20050007866Abstract: A method and circuit for timing the start of a precharge period in an eDRAM. The circuit including: a delayed lock loop circuit for receiving a clock signal and generating a control signal for adjusting an internal delay of the clock signal; and means for generating a delayed clock signal in response to the control signal. The means for generating the delayed clock signal is a multiple stage delay circuit, each stage of the multiple delay stage circuit connected in series and each stage individually responsive to the control signal.Type: ApplicationFiled: June 30, 2003Publication date: January 13, 2005Applicant: INTERNATIONAL BUSINESS MACHINES CORPORATIONInventors: Darren Anand, John Fifield, Harold Pilo
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Publication number: 20040263213Abstract: A constant current source extending the common-mode range comprises a differential pair of transistors connected to a third current source driving transistor. In an embodiment of the invention, the drains of the differential pair are coupled so as to obtain a common-mode voltage. The gate of the third transistor is connected to the drains of the differential pair in order to regulate current flowing through the third transistor. As the voltage decreases at the drain of the third transistor, the gate voltage on the third transistor increases to compensate for the lost voltage on the drain, thereby keeping the current constant even as the third transistor exits the saturation region.Type: ApplicationFiled: June 26, 2003Publication date: December 30, 2004Inventors: Oliver Kiehl, John A. Fifield
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Patent number: 6794901Abstract: An integrated circuit that includes a dynamic logic gate having an output node at which a logical output value of the logic gate is detected and also includes a circuit for selectable alteration of the soft error susceptibility of the dynamic logic gate.Type: GrantFiled: August 29, 2002Date of Patent: September 21, 2004Assignee: International Business Machines CorporationInventors: Kerry Bernstein, Philip G. Emma, John A. Fifield, Paul D. Kartschoke, Norman J. Rohrer, Peter A. Sandon
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Patent number: 6753590Abstract: A programmable element that has a first diode having an electrode and a first insulator disposed between the substrate and said electrode of said first device, said first insulator having a first value of a given characteristic, and an FET having an electrode and a second insulator disposed between the substrate and said electrode of said second device, said second insulator having a second value of said given characteristic that is different from said first value. The electrodes of the diode and the FET are coupled to one another, and a source of programming energy is coupled to the diode to cause it to permanently decrease in resistivity when programmed. The programmed state of the diode is indicated by a current in the FET, which is read by a sense latch. Thus a small resistance change in the diode translates to a large signal gain/change in the latch. This allows the diode to be programmed at lower voltages.Type: GrantFiled: July 8, 2002Date of Patent: June 22, 2004Assignee: International Business Machines CorporationInventors: John A. Fifield, Russell J. Houghton, William R. Tonti
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Patent number: 6729090Abstract: An insulative panel with transverse fiber reinforcements is provided and which is adopted for use with a plurality of building materials such as concrete to create a lightweight, high strength building panel having superior insulative properties.Type: GrantFiled: May 17, 2002Date of Patent: May 4, 2004Assignee: Oldcastle Precast, Inc.Inventors: Harold G. Messenger, Thomas G. Harmon, John A. Fifield, John M. Carson
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Patent number: 6711078Abstract: A writeback and refresh circuit for a direct sense architecture memory wherein a plurality of primary sense amps are connected to a global data line and also to bitlines, each of which is coupled to an array of memory storage cells which are selected for write and read operations by a plurality of wordlines. A single secondary sense amp receives analog level data from the primary sense amps over the global data line, and includes a restore/writeback circuit which digitizes the data and then returns the digitized data over the global data line to the primary sense amp and back into the memory. A 2-cycle read/writeback operation is used for each memory read cycle, a first cycle read operation, and a second cycle writeback operation. The 2-cycle destructive read architecture eliminates the need for a cache and complex caching algorithms.Type: GrantFiled: July 1, 2002Date of Patent: March 23, 2004Assignee: International Business Machines CorporationInventors: Ciaran J. Brennan, John A. Fifield, Jeremy K. Stephens, Daniel W. Storaska
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Publication number: 20040041590Abstract: An integrated circuit that includes a dynamic logic gate having an output node at which a logical output value of the logic gate is detected and also includes a circuit for selectable alteration of the soft error susceptibility of the dynamic logic gate.Type: ApplicationFiled: August 29, 2002Publication date: March 4, 2004Applicant: International Business Machines CorporationInventors: Kerry Bernstein, Philip G. Emma, John A. Fifield, Paul D. Kartschoke, Norman J. Rohrer, Peter A. Sandon
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Publication number: 20040036091Abstract: A programmable element that has a first diode having an electrode and a first insulator disposed between the substrate and said electrode of said first device, said first insulator having a first value of a given characteristic, and an FET having an electrode and a second insulator disposed between the substrate and said electrode of said second device, said second insulator having a second value of said given characteristic that is different from said first value. The electrodes of the diode and the FET are coupled to one another, and a source of programming energy is coupled to the diode to cause it to permanently decrease in resistivity when programmed. The programmed state of the diode is indicated by a current in the FET, which is read by a sense latch. Thus a small resistance change in the diode translates to a large signal gain/change in the latch. This allows the diode to be programmed at lower voltages.Type: ApplicationFiled: August 29, 2003Publication date: February 26, 2004Inventors: John A. Fifield, Russell J. Houghton, William R. Tonti
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Patent number: 6697293Abstract: A localized direct sense architecture circuit includes a large number (e.g. 8) of microcells, each having a primary sense amp PSA, coupled to one global data line which is coupled to one secondary sense amp SSA. Each PSA includes its own bias current device, which supplies bias current to sense devices in the PSA and is also used for precharge, such that the bias current does not flow along the highly capacitive global data line. With this technical approach, the size of each bias current supply device can be substantially reduced, and the number of PSAs on one global data line can be increased for increased layout density.Type: GrantFiled: April 12, 2002Date of Patent: February 24, 2004Assignee: International Business Machines CorporationInventors: Ciaran J. Brennan, John A. Fifield
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Publication number: 20040004269Abstract: A programmable element that has a first diode having an electrode and a first insulator disposed between the substrate and said electrode of said first device, said first insulator having a first value of a given characteristic, and an FET having an electrode and a second insulator disposed between the substrate and said electrode of said second device, said second insulator having a second value of said given characteristic that is different from said first value. The electrodes of the diode and the FET are coupled to one another, and a source of programming energy is coupled to the diode to cause it to permanently decrease in resistivity when programmed. The programmed state of the diode is indicated by a current in the FET, which is read by a sense latch. Thus a small resistance change in the diode translates to a large signal gain/change in the latch. This allows the diode to be programmed at lower voltages.Type: ApplicationFiled: July 8, 2002Publication date: January 8, 2004Applicant: International Business Machines CorporationInventors: John A. Fifield, Russell J. Houghton, William R. Tonti