With Capacitive Bootstrapping Patents (Class 327/390)
  • Patent number: 5828262
    Abstract: An ultra-low power pumped n-channel transistor output buffer with self-bootstrapping includes an n-channel pullup transistor as the primary pullup device. A gate-to-source capacitance C.sub.gs of the pullup transistor is used to self-bootstrap the input data signal. A pass n-channel transistor is connected between the input data signal, and the gate of the pullup transistor, and is biased on a gate terminal thereof by a charge pump having a voltage magnitude one device threshold higher than the device operating rail V.sub.cc. The pass transistor, so biased, permits the input data signal, which may have a magnitude of V.sub.cc, to charge C.sub.gs. An over-voltage can be developed on the gate of the pullup transistor by the self-bootstrapping effect of C.sub.gs. The pass transistor, in addition, so biased, prevents such over-voltage on the pullup transistors gate from being shorted to V.sub.cc through a driving device.
    Type: Grant
    Filed: September 30, 1996
    Date of Patent: October 27, 1998
    Assignee: Cypress Semiconductor Corp.
    Inventor: David B. Rees
  • Patent number: 5815026
    Abstract: An integrated circuit voltage multiplier 30 in a semiconductor substrate of a first conductivity type. The multiplier includes a diode 22, having a first voltage VDD applied to a first port thereof, the diode being made of: 1) a first well 12 of a second conductivity type formed in the substrate, being connected to a second voltage VB; 2) a second well 14 of the first conductivity type formed in the first well, having an electrical contact point comprising the first port of the diode; and 3) a third well 16 of the second conductivity type formed in the second well, having an electrical contact point comprising a second port of the diode. The multiplier also includes a capacitor C3, having a first contact thereof connected to the second port of the diode and having a third, pulsed voltage PH1 connected to a second contact of the capacitor.
    Type: Grant
    Filed: July 19, 1996
    Date of Patent: September 29, 1998
    Assignee: Texas Instruments Incorporated
    Inventors: Giovanni Santin, Giulio Marotta, Michael C. Smayling
  • Patent number: 5812009
    Abstract: A boost type equalizing circuit, being an equalizing circuit used in a signal reproducing circuit of memory device such as an optical disk drive and hard disk drive, and comprising boost units 4, 6, which is used for compensating distortion caused in reproduced signal of information recording medium, and compensating frequency characteristic of reproduced signal. The boost units 4, 6 are composed so that the numerator of the transfer function may have an even-number order term of fourth power or more of Laplace operator s. A boost equalizing circuit of excellent cut-off characteristic in high frequency range can be presented.
    Type: Grant
    Filed: November 14, 1995
    Date of Patent: September 22, 1998
    Assignee: Fujitsu Limited
    Inventor: Michio Matsuura
  • Patent number: 5812015
    Abstract: A boosting pulse generating circuit includes a first inverter circuit connected between a first potential node and a second potential node and receives an input signal. A second inverter circuit, connected between the first potential node and the second potential node through a diode connected MOS transistor, is connected to an input terminal and an output terminal. A capacitor is connected between an output terminal of the first inverter circuit and a node interconnecting the diode connected MOS transistor and second inverter circuit. A back gate of the MOS transistor is connected to the gate thereof. This circuit produces good performance even when powered by a low voltage source of operating potential.
    Type: Grant
    Filed: December 10, 1996
    Date of Patent: September 22, 1998
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventor: Youichi Tobita
  • Patent number: 5783962
    Abstract: A bootstrap circuit includes a transfer transistor and a driver transistor of the same channel type each having two channel terminals and a gate. A first signal terminal receives a first signal and a second signal terminal receives a second signal. One of the channel terminals of the transfer transistor is connected to the gate of the driver transistor. The other of the channel terminals of the transfer transistor is connected to the first signal terminal. One of the channel terminals of the driver transistor is connected to the second signal terminal. The other of the channel terminals of the driver transistor forms an output of the bootstrap circuit. A configuration generates a third signal and has an output connected to the gate of the transfer transistor. The second signal has an edge extending from a first level to a second level and beginning at a bootstrap time.
    Type: Grant
    Filed: July 8, 1996
    Date of Patent: July 21, 1998
    Assignee: Siemens Aktiengesellschaft
    Inventor: Johann Rieger
  • Patent number: 5777317
    Abstract: A boosting circuit comprises a power supply terminal, an output terminal a one-way element and a one-way element for charging. The one-way element comprises a plurality of stages connected in series across the power supply terminal and the output terminal in a forward direction going from the power supply terminal to the output terminal, with clock pulses being applied between each of the one-way element stages. The one-way element for charging is connected in parallel with the one-way element in the forward direction. It is therefore possible to provide a boosting circuit with an improved boosting voltage rise characteristic without having to change the size of the circuit elements.
    Type: Grant
    Filed: April 11, 1997
    Date of Patent: July 7, 1998
    Assignee: Sony Corporation
    Inventor: Yasuhito Maki
  • Patent number: 5777495
    Abstract: A device for copying a voltage (Ve) comprises a pair of series-connected MOS transistors, their sources forming a common point. The voltage (Ve) to be copied is applied between the gate of the first MOS transistor of the pair and a reference. Means are provided to inject a flux of electrons at a common point. A storage capacitor has a first terminal connected to the drain of the second MOS transistor and a second terminal designed to be biased. Means dictate a potential at the drain of the second MOS transistor and then let it vary so that the flux of electrons is stored in the storage capacitor while at the same time decreasing in the second MOS transistor to the benefit of the first one. The copied voltage Vs is available, after stabilization, between the first terminal of the storage capacitor and the reference. Application in particular to circuits for the reading of charges generated in a photosensitive matrix or photosensitive linear array.
    Type: Grant
    Filed: February 26, 1996
    Date of Patent: July 7, 1998
    Assignee: Thomson Tubes Electroniques
    Inventors: Marc Arques, Thierry Ducourant
  • Patent number: 5770967
    Abstract: The invention relates to a charge-pump control circuit for a power transistor including a driver circuit connected to a first supply voltage through a diode and to a second voltage through a switch and a first load. The driver circuit is connected to the power transistor, and the power transistor is linked to a pump capacitor. The power transistor is connected between a further supply voltage and a second load. The control circuit of the invention further includes a control logic circuit connected between the first supply voltage and the second voltage. The control logic circuit is connected to the driver circuit and to the switch, and the switch is connected between the power transistor and the first load. The switch is also connected to the driver circuit, and to a circuit for checking the charged state of the pump capacitor which is connected between the switch and the control logic circuit.
    Type: Grant
    Filed: January 31, 1996
    Date of Patent: June 23, 1998
    Assignee: SGS-Thomson Microelectronics S.r.1.
    Inventors: Angelo Alzati, Aldo Novelli
  • Patent number: 5767729
    Abstract: A distribution charge pump is disclosed that provides a high voltage output that can be used to write or erase EEPROM cells. The charge pump is enabled by a high (VCC) input signal, which is input to a pair of always-on pass transistors. The output of one of these pass transistors turns on a third transistor whose source is tied to an internal node that is coupled to one terminal of a MOS capacitor and the gate of a fourth transistor. The other terminal of the MOS capacitor is tied to a clock signal and the source and drain of the fourth transistor are tied respectively to the charge pump output and a high voltage power supply node (VPP). The capacitor stores charge on the internal node when the clock signal goes high and discharges when the clock signal goes low. Due to this discharge, the voltage at the internal node drops, which causes the third transistor to turn on and supply charge to the internal node, preventing the complete discharge of charges stored during the positive phase of the clock cycle.
    Type: Grant
    Filed: October 31, 1996
    Date of Patent: June 16, 1998
    Assignee: Integrated Silicon Solution Inc.
    Inventor: Paul Jei-Zen Song
  • Patent number: 5760638
    Abstract: A phase generator circuit cyclically produces a first pair of phase signals and a second pair of phase signals, comprising a first circuit to produce a first phase of each pair of phase signals, these first phase signals being non-overlapping and switching over between a voltage 0 and a voltage VCC, and second and third circuits for the production, from the first phase signals, respectively of the second phase of the first pair and the second phase of the second pair of phase signals, these second phase signals being non-overlapping with the first phase signals and switching over between a negative voltage -V and a voltage VCC. The disclosure finds application in the piloting of charge pump type of negative voltage generator circuit.
    Type: Grant
    Filed: June 13, 1996
    Date of Patent: June 2, 1998
    Assignee: SGS-Thomson Microelectronics S.A.
    Inventors: Alessandro Brigati, Nicolas Demange, Maxence Aulas, Marc Guedj
  • Patent number: 5760637
    Abstract: A programmable charge pump produces a selected one of a plurality of bipolar output voltages in response to a pump select input signal. Transistor switches in the charge pump are controlled by logic circuitry so as to provide the selected bipolar output voltages. The charge pump may include a power management circuit to optimize power consumption by varying the clock frequency based on the current being drawn by the load. The charge pump may be fabricated as an integrated circuit which supports a plurality of interface standards requiring different bipolar supply voltages.
    Type: Grant
    Filed: December 11, 1995
    Date of Patent: June 2, 1998
    Assignee: Sipex Corporation
    Inventors: Henry Wong, Paul S. Chan, Raymond W. B. Chow
  • Patent number: 5757228
    Abstract: An improved output driver circuit for a semiconductor integrated circuit device is provided. The output driver circuit receives a type select signal (.phi.1, /.phi.1) determined by bonding selection. When a heavy load circuit is connected to an output terminal (DQ), a signal (.phi.1) of low level and a signal (/.phi.1) of high level are provided, whereby transistors (18, 19) are turned on simultaneously in response to a data signal (Mo). When a light load circuit is connected to the terminal (DQ), a signal (.phi.1) of high level and a signal (/.phi.1) of low level are provided, whereby transistors (18, 19) are turned on at a different timing. More specifically, following charging of a light load by a transistor (18) having low mutual conductance, a transistor (19) is turned on. Therefore, noise generation can be flexibly suppressed by bonding selection.
    Type: Grant
    Filed: January 31, 1997
    Date of Patent: May 26, 1998
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Kiyohiro Furutani, Hideyuki Ozaki
  • Patent number: 5742196
    Abstract: A level-shifting circuit (LS.sub.A) including a series arrangement of a load resistor (R.sub.A), a main current path of an input transistor and a bipolar series transistor (T3.sub.A) arranged as a current source and having a parasitic transistor with a small current gain factor, which is obtained, for example, by wholly surrounding the comparatively weakly doped collector region with a comparatively heavily doped material of the same conductivity type as the collector region. When the input transistor (T1.sub.A) is not conductive a large amount of charge accumulates in the series transistor (T3.sub.A), which is then in saturation. When the input transistor (T1.sub.A) is turned on the accumulated charge causes an overshoot in the current (I.sub.A) through the level-shifter which overshoot compensates for the slow response as a result of the parasitic capacitance (PC.sub.A) at the node (N.sub.A).
    Type: Grant
    Filed: April 9, 1996
    Date of Patent: April 21, 1998
    Assignee: U.S. Philips Corporation
    Inventors: Robert J. Fronen, Johannes P. T. De Vries
  • Patent number: 5729172
    Abstract: In a booster circuit for use in a semiconductor integrated circuit device that includes: a voltage detection circuit for detecting the boosted voltage with respect to a reference voltage; a pulse oscillator circuit in which oscillation is controlled in accordance with the results of voltage detection; and a charge pump circuit that uses the oscillation pulses to charge capacitors and generates a boosted voltage; a transfer control circuit is inserted between the pulse oscillator circuit and the charge pump circuit that is composed of a transfer gate which is ON/OFF-controlled by the detection output of the voltage detection circuit and a latch circuit. When the boosted voltage is higher than the set value and the detection output changes to low level, this transfer gate is immediately turned OFF, the oscillation output immediately preceding the OFF state is latched in the latch circuit, and oscillation pulses are not transferred to the charge pump circuit.
    Type: Grant
    Filed: January 31, 1996
    Date of Patent: March 17, 1998
    Assignee: NEC Corporation
    Inventor: Shyuichi Tsukada
  • Patent number: 5723994
    Abstract: A spurious glitch elongation circuit is described. The spurious glitch elongation circuit will allow the restoration of the output level of a level boost driving circuit. The circuit has a one-sided delay chain to increase the pulse width of spurious glitches that are from one logic state to a second logic state and return to the first logic state, while minimizing spurious glitches that are from the second logic state to the first logic state and returned to the second logic state.
    Type: Grant
    Filed: June 10, 1996
    Date of Patent: March 3, 1998
    Assignee: Etron Technology, Inc.
    Inventors: Tah-Kang Joseph Ting, Chun Shiah, Bor-Doou Rong
  • Patent number: 5708373
    Abstract: When input signal IN rises to an "H" level, node N1 attain an "H" level, and output terminal OUT is charged to a level of VCC-V.sub.TH by n channel transistor. Capacitor is charged by the "H" level signal transmitted through inverters, and the charged potential is superimposed on output terminal OUT. When a short pulse is merged with input signal IN, RS flipflop is latched, and node N1 attains an "L" level, thereby discharging the voltage of the output terminal. When the output terminal attains an "L" level, NAND gate is opened and RS flipflop is reset, thereby raising the output terminal again to a boost voltage.
    Type: Grant
    Filed: February 8, 1996
    Date of Patent: January 13, 1998
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventor: Yoshinori Inoue
  • Patent number: 5705948
    Abstract: A boost circuit effects increasing current flow through an inductor and a switch when the switch is closed, and then, when the switch is open, directs the inductor current through a diode to charge a storage capacitor at the output. A logic circuit operates the switch. The switch is controlled on by sensing low current flow in the capacitor and off by sensing high current flow in the switch, so that inductor current is continuous.
    Type: Grant
    Filed: April 1, 1996
    Date of Patent: January 6, 1998
    Assignee: Delco Electronics Corporation
    Inventor: David Dale Moller
  • Patent number: 5694074
    Abstract: A semiconductor integrated circuit comprises a NAND gate which constitutes a previous stage circuit, a reset circuit, a charging circuit, and a capacitor for generating a boost potential. A signal of a node A expressing data and a signal of a node B expressing permission of outputting data are not only input to the NAND gate, but also to the reset circuit, and the output of the reset circuit is not only input to the charging circuit but also to the NAND gate; therefore, the previous stage circuit and the reset circuit are interlinked with the output signals. In the result, even in a case where noise is generated in the node A, it is possible to obtain a sufficient boost potential generated in the capacitor.
    Type: Grant
    Filed: December 29, 1995
    Date of Patent: December 2, 1997
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Osamu Kitade, Yutaka Ikeda
  • Patent number: 5689208
    Abstract: A high side monolithic switching circuit integrated into a silicon chip is described in which the charge pump is connected to the ground terminal by a constant current circuit and floats relative to the ground terminal to reduce noise generation. The charge pump is connected to a V.sub.CC terminal by an auxiliary power MOSFET having its gate connected to the charge pump output circuit. The conventional charge pump diodes are implemented as MOSFET devices which can be easily integrated into the common monolithic chip. A clamping circuit across the charge pump permits the use of a low voltage, small area capacitor for a high voltage device.
    Type: Grant
    Filed: June 12, 1996
    Date of Patent: November 18, 1997
    Assignee: International Rectifier Corporation
    Inventor: Bruno C. Nadd
  • Patent number: 5680071
    Abstract: In a dynamic random access memory (DRAM), first and second output transistors form an NMOS-type tristate output buffer. Interposed between a gate electrode of the first output transistor and a data input/output terminal (DQ terminal) is an auxiliary transistor of which gate electrode is grounded and of which threshold voltage is lower than that of the first output transistor. Further interposed between the DQ terminal and a gate electrode of the second output transistor is another auxiliary transistor of which gate electrode is grounded and of which threshold voltage is lower than that of the second output transistor. Both auxiliary transistors lower gate voltages of both output transistors down to a negative voltage level such that both output transistors are maintained as cut off when a negative voltage is externally applied to the DQ terminal at the time of high impedance.
    Type: Grant
    Filed: January 26, 1996
    Date of Patent: October 21, 1997
    Assignee: Matsushita Electronics Corporation
    Inventors: Manabu Senoh, Yoshitaka Mano, Akinori Shibayama
  • Patent number: 5672992
    Abstract: A high side monolithic switching circuit integrated into a silicon chip is described in which the charge pump is connected to the ground terminal by a constant current circuit and floats relative to the ground terminal to reduce noise generation. The charge pump is connected to a V.sub.cc terminal by an auxiliary power MOSFET having its gate connected to the charge pump output circuit. The conventional charge pump diodes are implemented as MOSFET devices which can be easily integrated into the common monolithic chip. A clamping circuit across the charge pump permits the use of a low voltage, small area capacitor for a high voltage device.
    Type: Grant
    Filed: April 11, 1995
    Date of Patent: September 30, 1997
    Assignee: International Rectifier Corporation
    Inventor: Bruno C. Nadd
  • Patent number: 5670909
    Abstract: A semiconductor device includes a boost circuit and a boost control circuit, wherein the boost control circuit comprises a first transistor connected to a load for outputting a boost voltage supplied thereto from a boost circuit to the load, a second transistor connected to the first transistor and further to the load, the second transistor being biased to turn on permanently, and a third transistor connected to the load via the second transistor, wherein the second transistor has a conductance exceeding a conductance of the third transistor.
    Type: Grant
    Filed: February 26, 1996
    Date of Patent: September 23, 1997
    Assignee: Fujitsu Limited
    Inventor: Kenichi Kawasaki
  • Patent number: 5646571
    Abstract: An output buffer circuit comprises a pair of first and second output MOS transistors coupled between a power supply line and a ground line; a booster circuit for boosting the power supply voltage up to a predetermined high voltage higher than a power supply voltage; a complementary MOS circuit comprising a pair of n-channel and p-channel MOS transistors connected in series between an output side of the booster circuit and the ground line; and a level shifter circuit having a first terminal coupled to an output side of a first logic gate for receiving logic signals from the first logic gate, a second terminal coupled to the gates of the n-channel and p-channel MOS transistors of the complementary MOS circuit and a third terminal coupled to the output side of the booster circuit for receiving the predetermined high voltage from the booster circuit, the level shifter circuit performing to shift the logic signal of the logic gate up to at least almost the same level as the predetermined high voltage to supply a s
    Type: Grant
    Filed: September 26, 1995
    Date of Patent: July 8, 1997
    Assignee: NEC Corporation
    Inventor: Masayuki Ohashi
  • Patent number: 5641986
    Abstract: A semiconductor device includes an increase voltage generation circuit generating an increased voltage having a higher potential than a high potential of a power-supply voltage externally supplied. In the device, an increased voltage stabilizing capacitor is connected between the increased voltage and the high potential of the power-supply voltage, and stabilizes the increased voltage.
    Type: Grant
    Filed: January 17, 1996
    Date of Patent: June 24, 1997
    Assignee: Fujitsu Limited
    Inventor: Toshiya Uchida
  • Patent number: 5621348
    Abstract: An improved output driver circuit for a semiconductor integrated circuit device is provided. The output driver circuit receives a type select signal (.phi.1, /.phi.1) determined by bonding selection. When a heavy load circuit is connected to an output terminal (DQ), a signal (.phi.1) of low level and a signal (/.phi.1) of high level are provided, whereby transistors (18, 19) are turned on simultaneously in response to a data signal (Mo). When a light load circuit is connected to the terminal (DQ), a signal (.phi.1) of high level and a signal (/.phi.1) of low level are provided, whereby transistors (18, 19) are turned on at a different timing. More specifically, following charging of a light load by a transistor (18) having low mutual conductance, a transistor (19) is turned on. Therefore, noise generation can be flexibly suppressed by bonding selection.
    Type: Grant
    Filed: May 23, 1995
    Date of Patent: April 15, 1997
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Kiyohiro Furutani, Hideyuki Ozaki
  • Patent number: 5594380
    Abstract: A bootstrap circuit comprising a capacitive device connected between an input line and an output line to boost a signal from the input line, a first voltage supply path being selectively driven in response to a voltage on the output line to transfer or block a supply voltage from a supply voltage source to the output line, a second voltage supply path connected in parallel to the first voltage supply path to transfer or block the supply voltage from the supply voltage source to the output line, and a controller for controlling the second voltage supply path in response to the signal from the input line. According to the present invention, the bootstrap circuit enhances a response speed of an output signal with respect to an input signal. Therefore, the bootstrap circuit can boost the input signal stably and accurately regardless of an impulse noise component.
    Type: Grant
    Filed: April 28, 1995
    Date of Patent: January 14, 1997
    Assignee: Hyubdai Electronics Industries Co., Ltd.
    Inventor: Jong G. Nam
  • Patent number: 5578961
    Abstract: A microwave monolithic integrated circuit (MMIC) RF-generated bias circuit and method includes an input for receiving an RF signal. A rectifier coupled to the input and to electrical ground produces a rectified RF signal in response. A voltage divider coupled to the rectifier and to the electrical ground receives the rectified RF signal and produces a DC voltage therefrom. An output is coupled to the voltage divider for applying the DC voltage to a MMIC field effect transistor (FET) for biasing. No separate bias battery is required, and efficiency is optimized because the generated bias voltage increases to the point where the amplifier voltage begins to decrease, which in turn reduces the generated bias voltage. The derived bias voltage may be used to control other circuits (e.g., other amplifiers, oscillators, mixers, etc.) which require detection of RF presence.
    Type: Grant
    Filed: January 16, 1996
    Date of Patent: November 26, 1996
    Assignee: Motorola, Inc.
    Inventors: Lyle A. Fajen, Michael Dydyk, Hugh R. Malone
  • Patent number: 5563545
    Abstract: A monolithic upconverter integrated circuit is described which performs the first frequency conversion of a dual conversion cable television (CATV) receiver. The upconverter chip includes three functional blocks: a Gilbert type image-rejecting mixer, a phase splitter, and a voltage-controlled oscillator. Mixing is performed by a novel Gilbert type mixer including image-rejection inductors to improve the noise figure of the mixer. A differential circuit topology allows the monolithic upconverter chip to utilize a plastic dual inline batwing package without considerable performance loss. On-chip RF bypass networks, in the form of series RC terminations, also help compensate for the undesirable effects of pin inductances in the dual inline package. A resistor-based DC biasing scheme dramatically reduces power-up latency, allowing faster testing.
    Type: Grant
    Filed: September 27, 1994
    Date of Patent: October 8, 1996
    Assignee: Anadigics, Inc.
    Inventor: Norman R. Scheinberg
  • Patent number: 5543750
    Abstract: An improved bootstrap circuit comprising a booster for boosting a binary signal and outputting the boosted binary signal through its output terminal, a voltage detector for detecting a variation of a supply voltage from a supply voltage source, and an active load for adjusting an output load amount of the booster under control of the voltage detector. According to the present invention, the binary signal is boosted to a voltage level which is stable regardless of the variation of the supply voltage.
    Type: Grant
    Filed: November 29, 1994
    Date of Patent: August 6, 1996
    Assignee: Hyundai Electronics Industries Co. Ltd.
    Inventor: Young N. Oh
  • Patent number: 5524036
    Abstract: A charge transfer device having an improved signal stage is disclosed. This stage includes a floating region formed in a semiconductor layer and receiving signal charges from a charge transfer stage, a reset drain region formed in the semiconductor layer adjacently to the floating region, a reset gate for resetting the floating drain region in potential to the reset drain region, an absorption region formed in the semiconductor layer adjacently to the reset drain region, a barrier gate supplied with a constant voltage to form a channel region between reset drain region and the adsorption region, and a charge injection source connected to the reset drain region to inject charges thereinto.
    Type: Grant
    Filed: May 27, 1994
    Date of Patent: June 4, 1996
    Assignee: NEC Corporation
    Inventor: Kazuo Miwada
  • Patent number: 5521546
    Abstract: A voltage boosting circuit is constructed together with a semiconductor memory device on a common substrate in an integrated circuit. The voltage boosting circuit comprises a first oscillating circuit, a boosted voltage Vpp main pumping circuit driven by the first oscillating circuit, a transmission gate for supplying Vpp in response to the output of the Vpp main pumping circuit, and a well bias supplying circuit for supplying a given bias to an isolation well on the substrate in which well the transmission gate is formed. The transmission gate includes a field effect transistor switched in common-source-amplifier configuration, rather than in common-drain-amplifier configuration, which mode of switching avoids unwanted voltage offset attributable to source-follower action.
    Type: Grant
    Filed: November 8, 1994
    Date of Patent: May 28, 1996
    Assignee: Samsung Electronics Co., Ltd.
    Inventor: Keum-Yong Kim
  • Patent number: 5514994
    Abstract: A bootstrap circuit particularly suitable for low voltage applications and use with semiconductor memories is disclosed.
    Type: Grant
    Filed: September 7, 1995
    Date of Patent: May 7, 1996
    Assignee: Nippon Steel Corporation
    Inventor: Kikuzo Sawada
  • Patent number: 5500612
    Abstract: A constant impedance sampling switch suitable for a high-frequency analog-to-digital converter, presents a substantially constant impedance to the input signal regardless of the instantaneous level of the input signal. The exemplary sampling switch employs a single metal oxide semiconductor (MOS) transistor to selectively couple the input signal to a sampling circuit. The gate signal for this transistor is generated by circuitry which is disconnected from the gate of the transistor while the transistor is in an non-conductive state. During a sampling interval, the gate signal is boot-strapped by the instantaneous potential of the input signal to render the transistor conductive. Accordingly, the potential difference between the signal being sampled and the gate potential of the transistor remains substantially constant over a relatively wide range of amplitudes for the analog input signal.
    Type: Grant
    Filed: May 20, 1994
    Date of Patent: March 19, 1996
    Assignee: David Sarnoff Research Center, Inc.
    Inventor: Donald J. Sauer
  • Patent number: 5499209
    Abstract: A word-line drive voltage generation circuit for use in a dynamic random-access memory is disclosed which is connected to a word line via a row decoder including MOS transistors. The circuit includes a charge-bootstrap capacitor having insulated electrodes, one of which is connected to a first reference voltage generator via a switching MOS transistor, and the other of which is connected via a MOS transistor to a second reference voltage generator. These voltage generators provide the capacitor with the constant d.c. voltage that are essentially insensitive to variation in the power supply voltage for the memory. The resultant word-line drive voltage may thus be free from variation in the power supply voltage during the operation modes of the memory. This enables the word-line voltage to be high enough to allow successful "H" level writing at a selected memory cell without creation of any unwantedly increased dielectric breakdown therein, in the entire allowable range of the power supply voltage.
    Type: Grant
    Filed: June 1, 1995
    Date of Patent: March 12, 1996
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Yukihito Oowaki, Daisaburo Takashima, Masako Ohta
  • Patent number: 5436587
    Abstract: A charge pump circuit comprises a plurality of voltage doubler circuits connected together such that a first voltage output generated by a first portion of a kth one of the voltage doubler circuits is substantially equal to Vdd*2.sup.k and Vdd*2.sup.k-1) on odd and even phases, respectively, of a first clock signal, and a second voltage output generated by a second portion of the kth one of the voltage doubler circuits is substantially equal to Vdd*2.sup.k-1) and Vdd*2.sup.k on the odd and even phases, respectively, of the first clock signal. Each of the voltage doubler circuits is constructed such that when its first portion is providing a voltage of Vdd*2.sup.k and a current to a next stage, its second portion is recharging a capacitor in that portion to Vdd*2.sup.k-1), and when its second portion is providing a voltage of Vdd*2.sup.2 and a current to the next stage, its first portion is recharging a capacitor in that portion to Vdd*2.sup.k-1).
    Type: Grant
    Filed: November 24, 1993
    Date of Patent: July 25, 1995
    Assignee: SunDisk Corporation
    Inventor: Raul-Adrian Cernea
  • Patent number: 5434531
    Abstract: An integrated circuit which includes a pair of serially arranged P channel transistor devices connected with their source and drain terminals in series. The devices are constructed as N well devices in a P substrate. Using a pair of N well devices allows higher voltages to be divided and applied across the two devices without reaching the breakdown limits of either the oxide or the junctions between different portions of the devices used in the process. These devices have been found capable of transferring ten or more volts to circuitry for programming or erasing flash EEPROM cells even the they are a part of integrated circuitry designed for only 3.3 volt usage.
    Type: Grant
    Filed: April 29, 1994
    Date of Patent: July 18, 1995
    Assignee: Intel Corporation
    Inventors: Michael J. Allen, Charles H. Lucas
  • Patent number: 5416437
    Abstract: A dual mode charge pump for an AGC circuit is described. The charge pump of the present invention provides normal and accelerated rates of charge and discharge of a capacitor used to control the gain of an AGC amplifier. Current sources for providing accelerated charge and discharge rates are deselected when not needed. Since these current sources consume substantial amounts of power, deselecting them increases efficiency and reduces unnecessary power consumption. The current sources may be deselected internally or may be switched off by a switches in series with the current sources. The present invention also may be used to provide a self-timing function. The self-timing function allows the AGC to acquire the correct gain in an optimum time after initiation by an external control signal.
    Type: Grant
    Filed: September 26, 1994
    Date of Patent: May 16, 1995
    Assignee: Silicon Systems, Inc.
    Inventors: Richard Contreras, Tim Jackson
  • Patent number: 5404053
    Abstract: An improved circuit for controlling the maximum current in a MOS power transistor, in which resistor is in series with the drain-source path of the MOS power transistor. The supply terminal of a transconductance operational amplifier is connected to the output of a voltage-raising or charge pump circuit which can output a voltage higher than that of the voltage supply to which the drain of the MOS transistor is connected. The inputs of the amplifier are connected to the resistor and its output is connected to the gate of the MOS transistor so that, in operation, the maximum current flowing through the power transistor is limited to a value proportional to a reference voltage.
    Type: Grant
    Filed: June 9, 1993
    Date of Patent: April 4, 1995
    Assignee: SGS-Thomson Microelectronics, S.r.l.
    Inventors: Alberto Poma, Vanni Poletto, Marco Morelli
  • Patent number: 5386151
    Abstract: A low voltage charge pump operable with a low voltage power supply and a clock signal is provided for delivering a final output voltage which is higher than the supply voltage. The low voltage charge pump comprises MOS capacitors formed of MOS devices, each capacitor including a p-well acting as a plate of the respective capacitor. Through this arrangement, the effective area of the capacitor is increased resulting in an increase in capacitance. Therefore, a more efficient charge pumping effect is provided in a low voltage power supply such as 3.3 volts. The p-well of each of the capacitor is driven from ground voltage to one threshold voltage less than the supply voltage to minimize forward bias of the p-wells and the n-type substrates of the MOS devices.
    Type: Grant
    Filed: August 11, 1993
    Date of Patent: January 31, 1995
    Assignee: Advanced Micro Devices, Inc.
    Inventor: Alan C. Folmsbee
  • Patent number: 5381051
    Abstract: A high voltage charge pump (65) for operation at low power supply voltages includes a plurality of series connected pump stages (66), a predriver logic circuit (68), and two pump driver circuits (70 and 72). The predriver logic circuit (68) receives an external clock signal and provides internal clock signals to the pump driver circuits (70 and 72). The pump driver circuits (70 and 72) provided boosted clock signals to the series connected pump stages (66). The boosted clock signals are provided at a voltage greater than a magnitude of a power supply voltage. By using a boosted clock signal, the charge pump (65) is capable of operating in applications with low power supply voltages, such as 3.3 volts.
    Type: Grant
    Filed: March 8, 1993
    Date of Patent: January 10, 1995
    Assignee: Motorola Inc.
    Inventor: Bruce L. Morton
  • Patent number: 5381044
    Abstract: In accordance with the present invention, the above and other objects and advantages are obtained with a bootstrap circuit for a power MOS transistor in a high side configuration. Such circuit includes a first capacitor chargeable to a first voltage which is a function of the supply voltage of the power transistor. It further includes a second capacitor combined with the first capacitor so as to provide a second voltage which is higher than the first voltage and the threshold voltage of the power transistor.
    Type: Grant
    Filed: July 22, 1992
    Date of Patent: January 10, 1995
    Assignees: Consorzio Per La Ricerca Sulla Microelettronica Nel Mezzogiorno, SGS-Thomson Microelectronics s.r.l
    Inventors: Michele Zisa, Massimiliano Belluso, Mario Paparo
  • Patent number: 5369320
    Abstract: An output buffer circuit comprises an input terminal for receiving an input signal, an output circuit coupled to a first node for outputting an output signal in response to a potential level appeared on the first node and a bootstrap circuit coupled between the first node and the input terminal. The bootstrap circuit comprises a delay circuit for delaying the input signal to provide a delayed input signal, a first transistor for receiving a signal inverted from the input signal, a second transistor coupled for receiving the delayed input signal and controlling a the first transistor, a third transistor connected in parallel to the second transistor, a fourth transistor coupled a gate of the third transistor for receiving the input signal and a charge circuit coupled between the delay circuit and the first node for supplying an electric charge to the first node. The charge circuit is activated in response to the potential level appeared on the first node and the delayed input signal.
    Type: Grant
    Filed: July 20, 1993
    Date of Patent: November 29, 1994
    Assignee: Oki Electric Industry Co., Ltd.
    Inventors: Norihiko Satani, Shizuo Cho
  • Patent number: 5365118
    Abstract: A driver circuit for driving top and bottom power transistors stacked between two supply terminals is provided. The driver circuit includes shoot-through reduction means for monitoring the gate-to-source voltages of the two power transistors so as to inhibit the turning-ON of each power transistor until the gate-to-source voltage of the other power transistor has fallen to a voltage level indicative of the other transistor being OFF. Additionally, the driver circuit which can utilize a bootstrap capacitor for providing enhanced voltages to drive the top power transistor, also includes a bootstrap capacitor recharge means to monitor the output voltage of the circuit so as to inhibit the turning-ON of the top power transistor until the bootstrap capacitor has had sufficient time to recharge.
    Type: Grant
    Filed: June 4, 1992
    Date of Patent: November 15, 1994
    Assignee: Linear Technology Corp.
    Inventor: Milton E. Wilcox