With Sensing Amplifier Patents (Class 327/51)
  • Patent number: 5694363
    Abstract: A device for reading memory cells, wherein the device contains two branches, wherein each branch comprises, connected in cascade, an electronic switch, an active element reactively connected to the active element of the other branch, so as to form a voltage amplifier. Each active element is controlled by means of a high impedance circuit element. A microswitch connects the two branches together is inserted between the two active elements.
    Type: Grant
    Filed: April 25, 1996
    Date of Patent: December 2, 1997
    Assignee: SGS-Thomson Microelectronics S.r.l.
    Inventors: Cristiano Calligaro, Roberto Gastaldi, Nicola Telecco, Guido Torelli
  • Patent number: 5689257
    Abstract: A differential switch accepts a binary control signal and its complement (which may be skewed with respect to the control signal) and latches both signals simultaneously. The latched output signals drive the control terminals of a differential switch pair which connects one of two terminals to a third terminal, depending upon the state of the control terminals. The differential switch may optionally include an inverter which complements the binary control signal, thus eliminating the need for external inversion of the control signal. The switch is particularly applicable for use in a digital to analog converter.
    Type: Grant
    Filed: January 5, 1996
    Date of Patent: November 18, 1997
    Assignee: Analog Devices, Inc.
    Inventors: Douglas A. Mercer, David Reynolds, David H. Robertson, Ernest T. Stroud
  • Patent number: 5687127
    Abstract: A semiconductor memory includes one pair of signal lines, and a plurality of memory cells connected to the plurality of word lines, respectively, and also connected to the one pair of signal lines in such a manner that when one of the plurality of word lines is activated, a potential difference corresponding to a content stored in the memory cell connected to the activated word line appears between the one pair of signal lines. A sense amplifier has a differential amplifier connected to the one pair of signal lines to output a signal in accordance with the potential difference appearing between the one pair of signal lines, and a feedback circuit composed of a flipflop for amplifying the potential difference appearing between the one pair of signal lines.
    Type: Grant
    Filed: February 9, 1996
    Date of Patent: November 11, 1997
    Assignee: NEC Corporation
    Inventor: Hiroyuki Takahashi
  • Patent number: 5684417
    Abstract: A data sensing apparatus particularly useful for sensing a ROM device. The apparatus can be used with various voltage level devices because it has an adjustable load. A first load element is connected to the voltage source applied to the ROM device. A second load element is connected in parallel with the first load element. A switching element is connected to the first load element and provides a path for a sensing current of the ROM device. An inverter, responsive to the sensing current, controls the switching element. An amplifier, connected to the switching element, provides a useful output indicative of the sensing current of the ROM device. A voltage level detector detects the voltage level of the voltage source. It disables the second load element so as to increase the load when the voltage level of the voltage source is higher than a predetermined value.
    Type: Grant
    Filed: November 14, 1995
    Date of Patent: November 4, 1997
    Assignee: United Microelectronics Corporation
    Inventors: Heng-Sheng Huang, Kun-Luh Chen
  • Patent number: 5682109
    Abstract: The present invention relates to a semiconductor integrated circuit. In greater detail, the present invention relates to a semiconductor integrated circuit which conducts calculations using a voltage adding function by means of capacity and threshold operations.
    Type: Grant
    Filed: February 13, 1996
    Date of Patent: October 28, 1997
    Assignees: Tadahiro Ohmi, Tadashi Shibata
    Inventors: Tadahiro Ohmi, Tadashi Shibata, Koji Kotani
  • Patent number: 5675266
    Abstract: A signal amplifying device including a sense amplifier for receiving first and second signals having respective logical levels from memory cells, and for, when activated in response to an actuating signal, outputting third and fourth signals having respective logical levels in accordance with the logical levels of the first and second signals; and output means for receiving the actuating signal, and the third and fourth signals, and for outputting an output signal having a logical level in accordance with a combination of the actuating signal and the logical levels of the third and fourth signals.
    Type: Grant
    Filed: June 24, 1996
    Date of Patent: October 7, 1997
    Assignee: Sharp Kabushiki Kaisha
    Inventor: Masahiro Kawate
  • Patent number: 5666310
    Abstract: An improved high-speed sense amplifier is disclosed for use in programmable logic devices (PLDs) and complex PLDs. The sense amplifier includes a transresistance amplifier portion that provides a voltage potential to a first node of a memory array, which defines a read product term line. The current drawn by the memory array will cause the output of the amplifier to change states once a predetermined current level is reached, the predetermined trip point indicating that at least one memory cell is conducting. The amplifier includes an n-channel MOS transistor having its drain connected between a second node of the memory array, and its source to ground. The gate of the n-channel transistor is connected to the read product line. The n-channel limits current through the memory array by raising the potential at the second node, thus reducing the voltage drop across the memory array.
    Type: Grant
    Filed: January 30, 1996
    Date of Patent: September 9, 1997
    Assignee: Cypress Semiconductor
    Inventors: Donald Yuen Yu, Jeffrey Scott Hunt, Satish Chandra Saripella, William Randolph Hiltpold
  • Patent number: 5666074
    Abstract: A sense amplifier power supply circuit for supplying a power source to a sense amplifier of a semiconductor memory device having two or more memory cell blocks is disclosed including a first power closed circuit for connecting a first power voltage line to a second ground voltage line, a second power closed circuit for connecting a first ground voltage line to a second power voltage line, a first switching transistor for supplying a power voltage to the first power closed circuit, a second switching transistor for supplying a ground voltage to the second power closed circuit, a third switching transistor for supplying the power voltage to the second power closed circuit, and a fourth switching transistor for supplying the ground voltage line to the first power closed circuit.
    Type: Grant
    Filed: May 15, 1996
    Date of Patent: September 9, 1997
    Assignee: LG Semicon Co., Ltd.
    Inventor: Jun-Hyun Chun
  • Patent number: 5666319
    Abstract: An integrated circuit pattern of a sense amplifier is disclosed. The sense amplifier includes a sense circuit connected to a memory array and a column gate. The sense circuit includes N-MOSFETs cross-coupled between paired bit lines. The column gate includes an N-MOSFET for connecting the bit line to a data line and an N-MOSFET for connecting the other bit line to another data line. The N-MOSFET contained in the sense circuit and the N-MOSFET contained in the column gate are integrated in one element region. Further, the N-MOSFET contained in the sense circuit and the N-MOSFET contained in the column gate are integrated in another element region.
    Type: Grant
    Filed: March 5, 1996
    Date of Patent: September 9, 1997
    Assignee: Kabushiki Kaisha Toshiba
    Inventor: Junichi Okamura
  • Patent number: 5659259
    Abstract: Small voltage changes on a highly capacitive signal are sensed rapidly by placing a shielding impedance between the signal to be sensed and the input to a regenerative sense circuit. A regenerative sense circuit has a sense amplifier which controls a switching means that is connected to the input to the sense amplifier. When the output of the sense amplifier reaches a threshold value, it turns the switching means on. This switching means increases the rate of change on the input to the sense amplifier which causes the switching means to turn on even more. The input and output of the sense amplifier are able to switch more rapidly because the shielding impedance allows the switching means to change the state of the input to the sense amplifier without having to completely change the voltage level on the highly capacitive input signal. A small voltage difference between two signals is sensed by two cross-coupled, actively loaded, NMOS inverters.
    Type: Grant
    Filed: April 12, 1996
    Date of Patent: August 19, 1997
    Assignee: Hewlett-Packard Company
    Inventor: Paul R. Bodenstab
  • Patent number: 5659513
    Abstract: A delay circuit delays an internal write control signal by a prescribed time to a global write driver. The global write driver is enabled in response to the delayed write control signal received from the delay circuit, to drive a global write data bus in accordance with internal write data from an input buffer. A block write driver is enabled in response to an internal write control signal and a block selection signal, to drive a local write data bus in response to data on the global write data bus. A write gate connects a bit line to the local write data bus in response to a column selection signal. The delay circuit sets the output of the block write driver at a low level for a prescribed period, whereby a precharge potential of the bit line is reduced to reduce the potential amplitude of the bit line in data writing. An SRAM which operates at a high speed with an enlarged write recovery time margin is provided. SRAM also includes various arrangement for improving operating characteristics and reliability.
    Type: Grant
    Filed: September 11, 1995
    Date of Patent: August 19, 1997
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Toshihiko Hirose, Shigeki Ohbayashi, Setsu Kondo, Takashi Hayasaka, Yoshiyuki Fujino, Masayuki Iketani
  • Patent number: 5654653
    Abstract: An I/O bus interface cell includes a driver circuit having an input terminal fed by a logic signal and an output terminal to produce in response thereto a drive signal having selectable rise and fall time characteristics in accordance with a reference voltage provided to the driver. The I/O cell also includes a receiver circuit having an input terminal coupled to said output terminal of said driver with the receiver disposed to latch an unresolved, unamplified received signal prior to resolving the state of the signal. The I/O cell further includes a termination circuit having a terminal connected to the output of said driver, and having a selectable impedance characteristic at said terminal, with said selectable impedance being in accordance with a reference voltage provided to an input of said termination circuit. Preferably, the I/O cell the driver, receiver and termination circuits are fabricated on a common semiconductor substrate.
    Type: Grant
    Filed: January 16, 1996
    Date of Patent: August 5, 1997
    Assignee: Digital Equipment Corporation
    Inventors: Joseph P. Coyle, William B. Gist
  • Patent number: 5654928
    Abstract: A current sense amplifier for use in a semiconductor memory device having a pair of sub-I/O lines and a pair of I/O lines includes a first circuit leg having a first PMOS transistor in series with a second NMOS transistor. A second circuit leg has a third PMOS transistor in series with a fourth NMOS transistor. The gates of the PMOS transistors are each cross coupled to the drain of the other PMOS transistor. The gates of the NMOS transistor are each cross coupled to the source of the PMOS transistor in the other circuit leg. The source of each PMOS transistor comprises a sub-Input/Output line with an Input/Output line located between the transistors in each of the legs.
    Type: Grant
    Filed: April 23, 1996
    Date of Patent: August 5, 1997
    Assignee: Samsung Electronics Co. Ltd.
    Inventors: Kyu-Chan Lee, Jai-Hoon Sim
  • Patent number: 5650971
    Abstract: Integrated circuit memory with bitlines which cross each other in multiple place for symmetric capacitives coupling. Also read only memory with differential sense amplifier with an input to each half array of cells. Bits are stored complementarily in the two halves.
    Type: Grant
    Filed: May 26, 1995
    Date of Patent: July 22, 1997
    Assignee: Harris Corporation
    Inventors: Charles William Tull Longway, William Ronald Young
  • Patent number: 5648935
    Abstract: A sense amplifier comprising a data refresh amplifier for supplying voltages to true and complementary bit lines in response to a first control signal to amplify true and complementary data on the true and complementary bit lines, respectively, a first transistor fox amplifying current of the true data on the true bit line in response to a second control signal and transferring the amplified true data to a true input/output line, a second transistor for amplifying current of the complementary data on the complementary bit line in response to the second control signal and transferring the amplified complementary data to a complementary input/output line, a first switch for selectively forming a current path between the true input/output line and the true bit line, and a second switch for selectively forming a current path between the complementary input/output line and the complementary bit line.
    Type: Grant
    Filed: May 22, 1995
    Date of Patent: July 15, 1997
    Assignee: Hyundai Electronics Industries Co., Ltd.
    Inventors: Yo Hwan Koh, Chan Kwang Park, Jeung Won Suh
  • Patent number: 5646887
    Abstract: Low-voltage-correcting bias circuitry for a sense amplifier includes first, second and third N-channel transistors. The channel of the first transistor couples a current mirror to the input terminal of the amplifier and the gate of the second transistor, the channel of the second transistor couples the gate of the first transistor to a reference terminal. The channel of the third transistor couples the supply voltage to the gate of the first transistor. The gate of the third transistor is coupled to a reference voltage. A P-channel transistor has a channel coupling the supply voltage to the gate of the first transistor. The gate of the P-channel transistor is coupled to a low-voltage-sensing signal. Pre-charge circuitry includes a nonvolatile memory cell and fourth, fifth and sixth N-channel transistors. The channel of the fourth transistor is in series with the channel of the memory cell. The channel of the fifth transistor couples the channel of the memory cell to the input of the sense amplifier.
    Type: Grant
    Filed: November 20, 1995
    Date of Patent: July 8, 1997
    Assignee: Texas Instruments Incorporated
    Inventors: Phat C. Truong, Tim M. Coffman
  • Patent number: 5638333
    Abstract: A bit line sensing circuit of a semiconductor memory device having NMOS and PMOS sense amps connected to a bit line includes a variable delay path for variably controlling an interval of the operating time between the NMOS and PMOS sense amps in response to a power voltage sensing signal generated by sensing a power voltage level.
    Type: Grant
    Filed: June 7, 1995
    Date of Patent: June 10, 1997
    Assignee: Samsung Electronics Co., Ltd.
    Inventor: Sang-Bo Lee
  • Patent number: 5631583
    Abstract: A reconfigurable sense amplifier in accordance with the present invention operates in either a high switching speed mode, where power consumption is a less critical consideration, or in a low power consumption mode, where switching speed is a less critical consideration. In a high speed mode, the present invention provides an additional pull-up to an amplified bitline which in combination with an existing weak pull-up still permits the signal on the amplified bitline to be affected by a change in voltage on the bitline. In a low power mode, the present invention provides a temporary pull-up on the amplified bitline if a signal on a wordline is transitioning from high to low (i.e. indicating that a low-to-high signal transition may occur on the bitline). In this manner, the present invention anticipates that when such a transition occurs, the voltage on the amplified bitline may also increase.
    Type: Grant
    Filed: July 8, 1996
    Date of Patent: May 20, 1997
    Assignee: Xilinx, Inc.
    Inventors: Napoleon W. Lee, Wei-Yi Ku
  • Patent number: 5625588
    Abstract: An integrated circuit dynamic memory device is described which stores data in memory cells as a charge on a capacitor. The memory cells can be selectively connected to a digit line. Sensing circuitry, including both p-sense and n-sense amplifiers, is connected to the digit line for sensing data stored in the memory cells. Equalization circuitry is described to equalize the sense amplifiers by connecting both nodes of the sense amplifiers to the digit line prior to sensing data stored on the memory cell.
    Type: Grant
    Filed: June 6, 1995
    Date of Patent: April 29, 1997
    Assignee: Micron Technology, Inc.
    Inventors: Mirmajid Seyyedy, Stephen L. Casper
  • Patent number: 5619149
    Abstract: A single-ended sense amplifier circuit for sensing the state of a bitline in a memory array. The sense amplifier includes an output circuit having an input and an output, the output for indicating a state of the bitline in response to a bitline voltage level. A precharge circuit is coupled to the input for charging the input to a first voltage level when the input is decoupled from the bitline. A discharge circuit is coupled between the bitline and the input. In one embodiment, the discharge circuit includes a field effect transistor coupled as a cascode device for coupling and decoupling the input to the bitline. The discharge circuit couples the input to the bitline when the discharge voltage level exceeds a threshold voltage level of the discharge circuit.
    Type: Grant
    Filed: February 15, 1995
    Date of Patent: April 8, 1997
    Assignee: Sun Microsystems, Inc.
    Inventors: Lavi A. Lev, Michael Allen
  • Patent number: 5614849
    Abstract: A SRCMOS sense amplifier is provided with a latch in the output stage. When a sense amplifier input signal propagates through the circuit and reaches the output stage, a reset signal is generated resetting and charging the input stage and an enable buffer stage of the amplifier to allow the input stage to begin receiving new data while previous data is latched in the output stage. An output stage reset enable is generated when data is at the output terminals of the output stage. The reset enable is combined with a clock signal in a separate output stage reset circuit to reset the circuit on a clocked basis. A further input to the output stage reset circuit is a feedback from a next circuit stage indicating that the data has been properly received in the next stage. The output stage may be reset either in response to the feedback signal from the next stage or in the presence of the reset enable and the clock signal.
    Type: Grant
    Filed: June 7, 1995
    Date of Patent: March 25, 1997
    Assignee: International Business Machines Corporation
    Inventor: Antonio R. Pelella
  • Patent number: 5610540
    Abstract: A low power sense amplifier to sense the output of any memory cell whose output may be ill-defined is especially suited for use with gain memory cells. The low power sense amplifier circuit is based on an inverter with a feedback loop with additional circuitry providing stability after signal sensing. The bit sense line is discharged before sensing and after sensing it is locked to either a logical "0" or a logical "1" corresponding to the logical value of the gain memory cell during a read cycle. The low power sense amplifier provides a logic output that is well defined with respect to the supply voltage and corresponds to the logic valve of gain memory cell. The low power sense amplifier has no bias current flow during signal sensing and no power consumption in the stand by mode. The present invention low power sense amplifier is capable of being shared by a first bit sense line and a second bit sense line.
    Type: Grant
    Filed: April 1, 1996
    Date of Patent: March 11, 1997
    Assignee: Siemens Aktiengesellschaft
    Inventors: Klaus Althoff, Wolfgang H. Krautschneider, Klaus J. Lau
  • Patent number: 5604451
    Abstract: A highly stable sense amplifier circuit for a RAM and ROM includes a bias generating circuit capable of changing a bias voltage corresponding to voltage shifts of data lines, and an amplifying circuit having a transistor, the conducting state of which is controlled by the bias voltage for amplifying the voltage differences of the data lines. When the voltage of the data lines shifts due to manufacturing deviations, the bias voltage also shifts but operates so as to compensate shifts of the transistor in the amplifying circuit, so that the sense amplifier circuit can amplify the voltage differences of the data lines in a stable manner. The sense amplifier circuit can be formed with switches for cutting off through-currents, so that the sense amplifier circuit or even the memory on which the sense amplifier circuit is formed can operate with low power consumption.
    Type: Grant
    Filed: August 14, 1995
    Date of Patent: February 18, 1997
    Assignee: Oki Electric Industry Co., Ltd.
    Inventor: Toshikazu Sakata
  • Patent number: 5592427
    Abstract: An object of the present invention is to provide a semiconductor device that permits easy and efficient testing. A nonvolatile semiconductor memory comprises word lines WLi and bit lines BLi, a memory cell matrix 17 consisting of nonvolatile memory cells Cij, a sense amplifier 15, a write/erase timing circuit 9 for performing timing control necessary for write and erase operations, and a status register 2 for storing the operating state of the memory at the completion of the operation of the circuit 9, wherein there are provided, outside the address of the memory cell matrix 17, two kinds of dummy cells, D1, D2, D3, . . . , whose values are fixed to different values that induce different outputs from the sense amplifier 15. A pass condition or a fail condition is generated by accessing the dummy cells.
    Type: Grant
    Filed: June 6, 1995
    Date of Patent: January 7, 1997
    Assignee: Fujitsu Limited
    Inventors: Sinsuke Kumakura, Hirokazu Yamazaki, Hisayoshi Watanabe, Yasushi Kasa
  • Patent number: 5585747
    Abstract: A differential sense amplifier is provided wherein a first amplifier stage is biased to minimize current consumption of all stages of the amplifier and to provide outputs of the first stage that are high enough in voltage to allow proper operation of a second stage of the amplifier, yet low enough in voltage to allow a current mirror to be integrated into the second stage of the amplifier. The integration of the third stage current mirror into the second stage amplifier reduces capacitive loading on the outputs of the second stage increasing speed while eliminating the extra power normally associated with a separate current mirror. This combination results in a very fast, yet very low power amplifier.
    Type: Grant
    Filed: October 11, 1994
    Date of Patent: December 17, 1996
    Inventor: Robert J. Proebsting
  • Patent number: 5585746
    Abstract: A current sensing circuit is described in which a pair of bipolar transistors are arranged with a pair of field effect transistors such that the field effect transistors absorb most of the supply voltage associated with a load.
    Type: Grant
    Filed: September 28, 1995
    Date of Patent: December 17, 1996
    Assignee: Honeywell Inc.
    Inventor: Ralph J. Franke
  • Patent number: 5577001
    Abstract: A differential to single ended sense amplifier utilizes a minimum number of stages to convert a differential input signal received from complementary bit lines to a single ended output signal indicative of the state of the data stored in a selected memory cell connected to the complementary bit lines. The circuit is constructed to operate with low voltage swings, thereby increasing the switching speed and thus the sense speed. The sense amplifier includes power down capabilities and the ability to tristate its output terminal while in a standby mode of operation during which it is capable of reading the logic level of an input signal. In one embodiment, the output signal is latched using a simple register when the output stage goes tristated, to continue to provide a valid output signal while a subsequent sense operation is performed.
    Type: Grant
    Filed: January 24, 1996
    Date of Patent: November 19, 1996
    Assignee: Sun Microsystems
    Inventor: Bal S. Sandhu
  • Patent number: 5576644
    Abstract: A high speed self-resetting, edge-triggered CMOS (SRCMOS) receiver and parallel L1/L2 latch combination are provided which may be used to receive and latch data from a single-ended input of static random access memory (SRAM) or a dynamic random access memory (DRAM). The invention comprises a true/complement generator circuit (TCG) for generating a data and its complement from a single-ended input, a reset circuit for automatically resetting the TCG independent of the system clock, and a parallel L1/L2 latch for storing the data for further processing. The L1/L2 latch preferably has scan-in and scan-out ports useful for testing and diagnostic purposes.
    Type: Grant
    Filed: June 2, 1995
    Date of Patent: November 19, 1996
    Assignee: International Business Machines Corporation
    Inventor: Antonio R. Pelella
  • Patent number: 5568073
    Abstract: According to the present invention, the delay associated with a logic stage external to a sense amplifier is eliminated by absorbing the logic state into the sense amplifier circuitry. The sense amplifier inputs are swapped based on a sense enable signal which may be a derivative signal of a Data In signal. The sense amplifier may sense continuously or it may be clocked. The sense enable circuitry may be applied to various types of sense amplifiers such as dynamic, current mirror, differential, cross coupled, and level shifting sense amplifiers.
    Type: Grant
    Filed: December 22, 1993
    Date of Patent: October 22, 1996
    Assignee: SGS-Thomson Microelectronics, Inc.
    Inventor: David C. McClure
  • Patent number: 5568066
    Abstract: A high density programmable logic device (PLD) having sense amplifiers and OR gates configured to increase operation speed and reduce transistor count from previous circuits as well as to provide a selectable power down mode on a macrocell-by-macrocell basis. The sense amplifiers include a single cascode in the data path connecting a product term to the OR gates. The OR gates utilize a plurality of source follower transistors followed by pass gates to provide logic allocation enabling the sense amplifier outputs to be reduced from the 0.0 V-5.0 V CMOS rails to increase switching speed while reducing overall transistor count. Amplifying inverters normally provided in the sense amplifiers to provide the CMOS rail-to-rail switching and which would require complex feedback for providing power down on a macrocell-by-macrocell basis are moved forward into OR output circuits. Power down on a macrocell-by-macrocell basis is provided by selectively sizing the amplifying inverters in the OR output circuits.
    Type: Grant
    Filed: November 17, 1994
    Date of Patent: October 22, 1996
    Assignee: Advanced Micro Devices, Inc.
    Inventors: Bradley A. Sharpe-Geisler, Fabiano Fontana
  • Patent number: 5563527
    Abstract: The present invention provides a configurable sense amplifier for a programmable logic device (PLD) that can be turned on or off as needed. Specifically, a latch stores an enable or disable state which respectively connects or disconnects the sense amplifier to a voltage source Vcc. In this manner, the sense amplifier remains on or off until the latch is reset. In one embodiment of the present invention, a reset circuit provides a predetermined value to the latch and a pass transistor to prevent floating during a power-on operation.
    Type: Grant
    Filed: April 21, 1995
    Date of Patent: October 8, 1996
    Assignee: Xilinx, Inc.
    Inventor: Sholeh Diba
  • Patent number: 5561629
    Abstract: A sense amplifier is provided that automatically determines its enabled/disabled state. The sense amplifier includes a latch to store the enable/disable signals. A global power-on-reset signal during initialization sets the state of this latch to a default configuration which disables, i.e. powers down, the sense amplifier. During configuration, an active latch enable signal forces the sense amplifier into an enable ready state. Then, a high signal is provided to each wordline associated with the bitline of the sense amplifier. This causes any erased memory cell driven by the wordlines to pull the associated bitline into a bitline low state and causes the sense amplifier output signal to switch states. This switch causes the latch to be overwritten with the opposite state, thereby enabling the sense amplifier. When the latch enable signal goes inactive after configuration of the device, the latch is set such that the sense amplifier remains enabled, i.e. powered up.
    Type: Grant
    Filed: March 10, 1995
    Date of Patent: October 1, 1996
    Assignee: XILINX, Inc.
    Inventor: Derek R. Curd
  • Patent number: 5559455
    Abstract: An integrated circuit is disclosed that includes a sense amplifier having first and second transistors, each of which have a conduction path and a gate electrode. The conduction path of the first and second transistors are electrically coupled in series between a power supply node and an input. The integrated circuit also includes third and fourth transistors each having a conduction path and a gate electrode. The conduction path of the third and fourth transistors are electrically coupled in series between the power supply node and a first reference potential. The gate electrodes of the first and third transistors are electrically coupled to an output node. A fifth transistor has a conduction path electrically coupled between a second reference potential and the output node. The gate electrode is maintained at a voltage that is about two threshold voltage drops below the voltage level of the power supply node.
    Type: Grant
    Filed: December 23, 1994
    Date of Patent: September 24, 1996
    Assignee: Lucent Technologies Inc.
    Inventor: Richard J. McPartland
  • Patent number: 5552728
    Abstract: A latch-type current sense amplifier circuit generates complementary latched data outputs indicative of a difference between first and second input currents provided to the sense amplifier circuit respectively via first and second input data lines. Included in the sense amplifier circuit are a latch circuit formed from cross-coupled inverters, a transmission gate responsive to a first control signal for equalizing the outputs of the sense amplifier circuit, and three transistors. The first transistor is responsive to a second control signal, activated after a delay after deactivation of the first control signal, for connecting a reference voltage to the latch circuit.
    Type: Grant
    Filed: May 1, 1995
    Date of Patent: September 3, 1996
    Assignee: Cirrus Logic, Inc.
    Inventor: Jyhfong Lin
  • Patent number: 5546068
    Abstract: There is disclosed an integrated circuit including a sense amplifier. The sense amplifier is capable of encoding 2.sup.n levels of output characteristic into a bit pattern of n corresponding bits. The sense amplifier includes a non-zero detect circuit for detecting when the output characteristic is zero. The sense amplifier also includes 2.sup.n -2 comparators for comparing an output characteristic to 2.sup.n -2 reference levels when the output characteristic is non-zero. The 2.sup.n -2 reference levels are constructed from 2.sup.n -2 non-zero levels of the 2.sup.n possible levels of output characteristic. An encoder is coupled to the non-zero detect circuit and the comparators. The encoder encodes the output from the non-zero detect circuit and the outputs from the comparators to corresponding predetermined bit patterns. When the output characteristic is determined to be zero by the non-zero detect circuit, the bit pattern output is a default bit pattern.
    Type: Grant
    Filed: December 22, 1994
    Date of Patent: August 13, 1996
    Assignee: AT&T Corp.
    Inventor: Aaron L. Fisher
  • Patent number: 5543738
    Abstract: A multi-stage sense amplifier for read-only memory having a memory array consisting of a large number of memory cell units. The sense amplifier includes a sense amplifier for sensing the currents flowing through the transistor of the memory cell units of the read-only memory. The memory cell unit transistors are programmed with one of four current capacity characteristics. The sense amplifier also includes three current comparators coupled to the sense amplifier, with each of the comparators having a current comparing unit for comparing the sensed current flowing through the memory cell unit transistors to the current flowing through the comparators. An output of each of the three comparators is provided for identifying whether or not the current of a four capacity characteristics flowing through the memory cell unit transistors is larger than the current flowing through the comparator.
    Type: Grant
    Filed: December 27, 1994
    Date of Patent: August 6, 1996
    Assignee: United Microelectronics Corp.
    Inventors: Fong-Chun Lee, Chien-Chih Fu, Nan-Chueh Wang
  • Patent number: 5541526
    Abstract: The multiple-input OR-gate includes a set of pull down transistors connected in parallel to a common signal line. A pair of first and second inverters are connected along the common signal line between the input pull down transistors and an output. A feedback element connects an output of the second inverter to an input of the first inverter. The inverters are configured to maintain the input of the first inverter at a first intermediate voltage level of V.sub.cc -2 Vt. Input signals received by the input transistors cause the voltage on the signal line to be pulled from the first intermediate level toward Vss. The first inverter responds by generating an output signal which swings from a low voltage of V.sub.ss towards a second intermediate level of V.sub.cc -0.7 Vt. The second inverter responds by generating an output signal which swings between the high level of V.sub.cc and a low level of V.sub.ss.
    Type: Grant
    Filed: June 7, 1995
    Date of Patent: July 30, 1996
    Assignee: Sun Microsystems, Inc.
    Inventor: Bal S. Sandhu
  • Patent number: 5539339
    Abstract: A load stage including a first transistor whose channel is connected between a first terminal and a first node, a second transistor whose channel is connected between a second terminal and a second node, a third transistor whose channel is connected between the first node, a third terminal and a fourth transistor whose channel is connected between the second node and the third terminal and a switch between the first and the second terminal. The gates of the first and the fourth transistor are connected to the first terminal. The gates of the second and the third transistor are connected to the second terminal. The load stage also includes a switch connected between the first node and the second node. When the switch is closed the first and the second transistor form a positive differential impedance between the first and the second terminal. When the switch is open the cross-coupled third and fourth transistors form a negative differential impedance between the first and the second terminal.
    Type: Grant
    Filed: October 18, 1995
    Date of Patent: July 23, 1996
    Assignee: U.S. Philips Corporation
    Inventor: Antonia C. Van Rens
  • Patent number: 5537356
    Abstract: When a current flows through a selected memory cell transistor at the time of data reading, the gate voltage of an n-channel MOS transistor, which makes up the current flowing through the load, rises. Thus, when a current flows through a selected memory cell transistor at the time of data reading, the current through the load is increased so that the time required for data reading when the current flows through the selected memory cell transistor can be shortened and the data reading can be effected at a high speed.
    Type: Grant
    Filed: June 5, 1995
    Date of Patent: July 16, 1996
    Assignee: Fujitsu Limited
    Inventors: Takao Akaogi, Masanobu Yoshida, Yasushige Oqawa, Yasushi Kasa, Shouichi Kawamura
  • Patent number: 5534800
    Abstract: A sense amplifier for an SRAM providing both a small power consumption and a high speed sensing operation.
    Type: Grant
    Filed: October 7, 1993
    Date of Patent: July 9, 1996
    Assignee: Hitachi, Ltd.
    Inventors: Mitsuru Hiraki, Yasuhiko Sasaki, Koichi Seki, Tatsuji Matsuura
  • Patent number: 5532623
    Abstract: A sense amplifier includes: a pull-down device which contains a reference cell which is structurally identical to the PLD cells being sensed; and a pull-up device connected to form a current mirror which causes a saturation current of the pull-up device to be zero or greater than the current through the sensed cell. The pull-down device has a saturation current which tracks the current through the sensed cell. When current flows through the sensed cell, saturation current through the pull-up device exceeds the saturation current through the pull-down device, and an output node is pulled up. When no current flows through the sensed cell, no current flow through the pull-up device, and the pull-down device pulls the output node down. As a result, the sense amplifier exhibits a variable trip point which tracks variations cause by changes in device fabrication process, temperature, and power supply voltage.
    Type: Grant
    Filed: October 21, 1994
    Date of Patent: July 2, 1996
    Assignee: WaferScale Integration, Inc.
    Inventors: Manik Advani, Cuong Trinh
  • Patent number: 5530384
    Abstract: A reconfigurable sense amplifier in accordance with the present invention operates in either a high switching speed mode, where power consumption is a less critical consideration, or in a low power consumption mode, where switching speed is a less critical consideration. In a high speed mode, the present invention provides an additional pull-up to an amplified bitline which in combination with an existing weak pull-up still permits the signal on the amplified bitline to be affected by a change in voltage on the bitline. In a low power mode, the present invention provides a temporary pull-up on the amplified bitline if a signal on a wordline is transitioning from high to low (i.e. indicating that a low-to-high signal transition may occur on the bitline). In this manner, the present invention anticipates that when such a transition occurs, the voltage on the amplified bitline may also increase.
    Type: Grant
    Filed: April 27, 1995
    Date of Patent: June 25, 1996
    Assignee: Xilinx, Inc.
    Inventors: Napoleon W. Lee, Wei-Yi Ku
  • Patent number: 5528545
    Abstract: A semiconductor memory device includes a plurality of sense amplifiers for amplifying current changes which occur in corresponding bit line pairs in accordance with binary signals stored in activated memory cells. Each of the sense amplifiers includes first and second current mirror circuits for generating currents of the magnitudes respectively corresponding to currents flowing through a corresponding bit line pair, a storing circuit, responsive to a signal selecting a memory cell, for storing the currents generated by the first and second current mirror circuits before activation of the memory cell, or a difference between these currents, and a current supplying circuit, responsive to activation of the memory cell and based on the amount stored in the storing circuit, for supplying, to the first and second current mirror circuits, currents having a predetermined relationship with the currents having been generated by the first and second current mirror circuits before activation of the memory cell.
    Type: Grant
    Filed: January 6, 1995
    Date of Patent: June 18, 1996
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Jun Takahashi, Tomohisa Wada
  • Patent number: 5528178
    Abstract: A SRCMOS sense amplifier is provided with a latch in the output stage. When a sense amplifier input signal propagates through the circuit and reaches the output stage, a reset signal is generated resetting and charging the input stage and an enable buffer stage of the amplifier to allow the input stage to begin receiving new data while previous data is latched in the output stage. An output stage reset enable is generated when data is at the output terminals of the output stage. The reset enable is combined with a clock signal in a separate output stage reset circuit to reset the circuit on a clocked basis. A further input to the output stage reset circuit is a feedback from a next circuit stage indicating that the data has been properly received in the next stage. The output stage may be reset either in response to the feedback signal from the next stage or in the presence of the reset enable and the clock signal.
    Type: Grant
    Filed: March 31, 1995
    Date of Patent: June 18, 1996
    Assignee: International Business Machines Corporation
    Inventor: Antonio R. Pelella
  • Patent number: 5525917
    Abstract: The present invention is a sense amplifier circuit for use with programmable logic devices, that provides improved switching time by actively limiting the voltage swing on the bit line which it is sensing, rather than passively sensing the voltage, and that employs feedback circuits to further improve switching time. Voltage reference control circuitry, comprising variable current limiters controlled by the potential of a supply of reference potential, can be added to improve noise immunity. The circuitry of the supply of reference potential is designed so that its sensitivity to fabrication variations is substantially similar to that of the sense amplifier and so that it adjusts the reference potential accordingly.
    Type: Grant
    Filed: December 16, 1994
    Date of Patent: June 11, 1996
    Assignee: Altera Corporation
    Inventors: Myron W. Wong, Dirk A. Reese, John C. Costello
  • Patent number: 5526314
    Abstract: A sense amplifier apparatus for use in a memory array having a plurality of memory cells is provided. The sense amplifier apparatus includes a differential sense amplifier and a dynamic sense amplifier. The differential sense amplifier has a first set of switches for driving the voltages of the sense amplifier apparatus and are coupled to a complementary pair of outputs. Also provided are a second set of switches, which are coupled to a complementary pair of input lines so as to amplify the input signal on either of the pair of input lines to a first signal level at a first rate of amplification. The dynamic sense amplifier shares the first set of switches with the differential sense amplifier and further includes a third set of switches that are coupled to a complementary pair of input lines and the output lines and also a sense enable line. This allows the first signal level to be amplified to a second signal level at a second rate of amplification faster than the first rate of amplification.
    Type: Grant
    Filed: December 9, 1994
    Date of Patent: June 11, 1996
    Assignee: International Business Machines Corporation
    Inventor: Manoj Kumar
  • Patent number: 5525918
    Abstract: A pre-sense amplifier (10) is disclosed. The pre-sense amplifier (10) increases a low-going bit line signal from a cell column (24) by an amount approximately equal to the threshold voltage of an n-channel MOS transistor. The pre-sense amplifier (10) includes a first channel (12) and a second channel (14), each channel having a precharge/transfer transistor (16) and an output precharge transistor (18). The output precharge transistors (18) are clocked to pull the inputs to a sense amplifier (26) to a positive supply voltage. At the same time, the precharge/transfer transistors (16) precharge the bit lines of a cell column (24) to a voltage equal to the positive supply voltage less their threshold voltage. When the cell column (24) pulls one of the bit lines low, the corresponding precharge/transfer transistor (16) connects the bit line with the sense amplifier input, redistributing the charge across the bit line capacitance and the sense amplifier input capacitance.
    Type: Grant
    Filed: December 27, 1994
    Date of Patent: June 11, 1996
    Assignee: Alliance Semiconductor Corporation
    Inventor: Chitranjan N. Reddy
  • Patent number: 5524097
    Abstract: A sense amplifier of the present invention provides power savings of between 30% to 70% for typical usage of a programmable logic device. In one embodiment, this sense amplifier includes circuitry for detecting and propagating the logic state on a bit line, an amplifier for amplifying the propagated logic state, and configuration logic for receiving a first configuration bit and a second configuration bit. If the first configuration bit and the second configuration bit have different logic states (indicating a non-toggling state), then the sense amplifier mimics the bit line at either a first logic state or a second logic state. Specifically, if the first configuration bit has the first logic state and the second configuration bit has the second logic state, then the sense amplifier mimics the bit line at the first logic state.
    Type: Grant
    Filed: March 3, 1995
    Date of Patent: June 4, 1996
    Assignee: Xilinx, Inc.
    Inventor: Napoleon W. Lee
  • Patent number: 5521875
    Abstract: A synchronous sense amplifier stage includes means for shunting the signal input terminal of the sense amplifier stage to ground during a precharge interval for discharging charge on a read bit line connected to the input terminal of the synchronous sense amplifier during the precharge interval. Means are also provided for precharging predetermined internal nodes and the output terminal of the synchronous sense amplifier stage to predetermined voltages during the precharge interval.
    Type: Grant
    Filed: December 30, 1994
    Date of Patent: May 28, 1996
    Assignee: VLSI Technology, Inc.
    Inventor: John M. Callahan
  • Patent number: 5514980
    Abstract: A high resolution sense amplifier and method for sensing the state of antifuses in an integrated circuit is capable of correctly reading even a defectively programmed antifuse having a resistance of up to 20 K.OMEGA. as being programmed. The sense amplifier reads two antifuses at each programmable location, and correctly reads that location as being programmed if either or both of the antifuses at that location have been blown.
    Type: Grant
    Filed: May 31, 1995
    Date of Patent: May 7, 1996
    Assignee: Integrated Device Technology, Inc.
    Inventors: David J. Pilling, Raymond M. Chu, Sik K. Lui