Ensuring Fully Conducting State Patents (Class 327/383)
  • Patent number: 10978581
    Abstract: Implementations of semiconductor devices may include: a plurality of drain fingers and a plurality of source fingers interdigitated with one another; at least one gate; and at gate bus formed to completely surround the plurality of drain fingers and the plurality of source fingers; wherein the gate bus is mechanically and electrically coupled to the at least one gate.
    Type: Grant
    Filed: April 18, 2019
    Date of Patent: April 13, 2021
    Assignee: SEMICONDUCTOR COMPONENTS INDUSTRIES, LLC
    Inventors: Woochul Jeon, Chun-Li Liu, Ali Salih
  • Patent number: 10530108
    Abstract: An USB hub including a power input port, a main power converting circuit, a first and a second type-C USB ports, and a first and a second power converting circuits is provided. The power input port receives an input power. The main power converting circuit converts the input power into a main power. The first and the second power converting circuits receive the main power respectively, and are coupled to the first and the second type-C USB ports respectively. The first and the second power converting circuits respectively obtain a first and a second operation power information of a first and a second external electronic devices, and respectively generate and provide a first and a second operating powers required by the first and the second external electronic devices for normal operation according to the first and the second operation power information.
    Type: Grant
    Filed: November 6, 2017
    Date of Patent: January 7, 2020
    Assignee: FSP TECHNOLOGY INC.
    Inventor: Chia-Ming Liu
  • Patent number: 10263506
    Abstract: A switch module includes a collector connection, an emitter connection, and a gate connection. The switch module includes a plurality of parallel connected switching elements, e.g., insulated-gate bipolar transistors, each having a collector electrode electrically connected to the collector connection, an emitter electrode electrically connected to the emitter connection, and a gate electrode electrically connected to the gate connection. A fault protection device is operatively electrically connected between the gate connection and the switching elements and comprises passive electrical components which are selected such that in the event of a fault in at least one of the plurality of switching elements, a gate-emitter voltage is provided to the gate electrodes of non-faulty switching elements in a passive manner.
    Type: Grant
    Filed: March 4, 2016
    Date of Patent: April 16, 2019
    Assignee: GE ENERGY POWER CONVERSION TECHNOLOGY LTD
    Inventors: Thomas Brueckner, Roland Jakob
  • Patent number: 9692414
    Abstract: In one embodiment, an inverter generates an inverted clock signal using (i) first P-type and N-type transistors connected in cascode between supply and ground nodes and (ii) control circuitry receiving different phase-offset input clock signals that ensure that the cascode-connected transistors are never even partially on at the same time, thereby preventing crowbar current from occurring through the cascode-connected devices. In one implementation, the control circuitry has two P-type transistors and two N-type transistors configured to receive three phase-offset input clock signals to prevent crowbar current in the inverter. The control circuitry has pass transistors that selectively allow one of the phase-offset input signals to be applied to the gate of one of the cascode-connected transistors with minimal delay, thereby enabling the inverter to operate properly over a relatively wide range of input clock frequencies.
    Type: Grant
    Filed: July 8, 2015
    Date of Patent: June 27, 2017
    Assignee: Lattice Semiconductor Corporation
    Inventor: Edward Miller
  • Patent number: 9293986
    Abstract: Kickback current from a charge pump to a power management integrated circuit (PMIC) may be reduced by dissipating charge from fly and hold capacitors during mode transitions. A switch may be placed in series between the charge pump and the PMIC to disconnect the charge pump and prevent kickback current from reaching the PMIC. Further, additional loads, as switches, may be coupled to the charge pump outputs to dissipate charge from the fly and hold capacitors. Additionally, a closed feedback loop may be used to monitor and discharge excess charge from the fly and hold capacitors during mode transitions. Furthermore, charge may be redistributed between the fly and hold capacitors during mode transitions to reduce the time period of the transition.
    Type: Grant
    Filed: December 16, 2013
    Date of Patent: March 22, 2016
    Assignee: CIRRUS LOGIC, INC.
    Inventors: Bharath Kumar Thandri, Thuan L. Nguyen, Daniel John Allen, Lingli Zhang, Aniruddha Satoskar, Aaron Brennan, Dan Shen
  • Publication number: 20150102735
    Abstract: The present invention relates to a gate driving circuit, and a array substrate and a display using the same.
    Type: Application
    Filed: January 23, 2014
    Publication date: April 16, 2015
    Inventor: Ping-Sheng Kuo
  • Patent number: 9000827
    Abstract: A system includes at least two power semiconductor chips being connected in parallel and including each a gate terminal for switching the power semiconductor chip in a blocking-state by a first gate voltage and for switching the power semiconductor chip in a conducting-state by a second gate voltage. The system includes further a control device adapted for applying the first or the second gate voltage to the gate terminals of the at least two power semiconductor chips. The control device is adapted for applying a third gate voltage to the gate terminal of the at least one remaining power semiconductor chip when a power semiconductor chip fails, and that the third gate voltage is higher than the second gate voltage.
    Type: Grant
    Filed: December 1, 2010
    Date of Patent: April 7, 2015
    Assignee: ABB Technology AB
    Inventors: Sven Klaka, Samuel Hartmann
  • Patent number: 8970258
    Abstract: In accordance with embodiments of the present disclosure, systems and methods may include a switch coupled at its gate terminal to an input signal voltage, the input signal voltage for controlling a gate voltage of a gate terminal of a driver device coupled at its non-gate terminals between a rail voltage and an output node. The systems and methods may also include a diode having a first terminal and a second terminal, the diode coupled to a non-gate terminal of the switch such that when the switch is enabled, the first terminal is electrically coupled to the gate terminal of the driver device and the second terminal is electrically coupled to the output node.
    Type: Grant
    Filed: March 14, 2013
    Date of Patent: March 3, 2015
    Assignee: Cirrus Logic, Inc.
    Inventors: Dan Shen, Johann Gaboriau, Lingli Zhang, Christian Larsen
  • Patent number: 8866516
    Abstract: A gate drive circuit includes: an input port for receiving a control signal; an output port; a capacitor connected to the output port; a modulation unit which generates (i) a first modulated signal indicating timing of a first logical value of the control signal and (ii) a second modulated signal indicating timing of at least a second logical value of the control signal; a first electromagnetic resonance coupler which wirelessly transmits the first modulated signal; a second electromagnetic resonance coupler which wirelessly transmits the second modulated signal; a first rectifier circuit which generates a first demodulated signal by demodulating the first modulated signal, and outputs the first demodulated signal to the output port; and a second rectifier circuit which generates a second demodulated signal by demodulating the second modulated signal, and outputs the second demodulated signal to the output port.
    Type: Grant
    Filed: October 25, 2013
    Date of Patent: October 21, 2014
    Assignee: Panasonic Corporation
    Inventors: Shuichi Nagai, Daisuke Ueda, Nobuyuki Otsuka
  • Patent number: 8829975
    Abstract: A method and corresponding circuits for operating a parallel DMOS switch that includes a pair of P-type DMOS devices connected in series with each other and in parallel with a pair of N-type DMOS devices connected in series with each other. The method and circuits involve turning the switch on by applying gate signals to the DMOS device pairs which are generated using at least one source voltage of a DMOS device pair. The switch is turned off by setting the gate signals equal to the respective source voltages of the DMOS device pairs.
    Type: Grant
    Filed: November 12, 2012
    Date of Patent: September 9, 2014
    Assignee: Analog Devices, Inc.
    Inventor: David Aherne
  • Publication number: 20140176033
    Abstract: There is provided a driving circuit including: a signal delay unit including a first delay unit delaying a high level input signal in a case in which an input signal has a high level, and a second delay unit delaying a low level input signal when the input signal has a low level; a signal output unit including first and second transistors connected to the first and second delay units and performing a switching operation under the control of the first and second delay units, respectively; and an output holding unit maintaining an output voltage at a level equal to that immediately before the first and second transistors are turned off, when the first and second transistors are simultaneously turned off.
    Type: Application
    Filed: February 26, 2013
    Publication date: June 26, 2014
    Applicant: SAMSUNG ELECTRO-MECHANICS CO., LTD.
    Inventors: Chang Jae HEO, Sung Man PANG
  • Publication number: 20140111268
    Abstract: A transistor control circuit includes: an electrode control circuit configured to apply a positive potential to a control electrode in a transistor that includes the control electrode between a gate and a drain.
    Type: Application
    Filed: August 14, 2013
    Publication date: April 24, 2014
    Applicant: FUJITSU LIMITED
    Inventor: Tadahiro Imada
  • Patent number: 8698356
    Abstract: Provided is a digital circuit (30) that comprises: a switching circuit (31) having first transistors (32, 33) supplied with power supply potentials (VDD, VSS); correcting circuits (34, 36) connected between an input terminal (IN) inputted with an input signal and control terminals (gates) of the first transistors; capacitors (C2, C3) connected between the control terminals and the input terminal; diode-connected second transistors (35, 37) that are provided between nodes (N5, N6) between the capacitors and the control terminals and the power supply potentials and have the substantially same threshold voltage as the first transistors; and switches (SW2, SW3) connected in series with the second transistors.
    Type: Grant
    Filed: November 13, 2012
    Date of Patent: April 15, 2014
    Assignee: Semiconductor Energy Laboratory Co., Ltd.
    Inventor: Hajime Kimura
  • Publication number: 20130249620
    Abstract: A method and corresponding circuits for operating a parallel DMOS switch that includes a pair of P-type DMOS devices connected in series with each other and in parallel with a pair of N-type DMOS devices connected in series with each other. The method and circuits involve turning the switch on by applying gate signals to the DMOS device pairs which are generated using at least one source voltage of a DMOS device pair. The switch is turned off by setting the gate signals equal to the respective source voltages of the DMOS device pairs.
    Type: Application
    Filed: November 12, 2012
    Publication date: September 26, 2013
    Applicant: Analog Devices, Inc.
    Inventor: David Aherne
  • Patent number: 8519751
    Abstract: A gate drive circuit capable of turning on a semiconductor switching element at high speed, which includes: a buffer circuit including a turn-on-drive switching element and a turn-off-drive switching element that are complementarily turned on and off, for driving the semiconductor switching element; a first DC voltage supply including a positive electrode connected to the source or emitter of the turn-on-drive switching element and a negative electrode connected to a reference potential; and a second DC voltage supply including a positive electrode connected to the source or emitter of the turn-off-drive switching element and a negative electrode connected to the reference potential.
    Type: Grant
    Filed: September 2, 2010
    Date of Patent: August 27, 2013
    Assignee: Mitsubishi Electric Corporation
    Inventors: Tatsuya Kitamura, Hiroshi Nakatake, Yasushi Nakayama
  • Patent number: 8314514
    Abstract: Provided is a digital circuit (30) that comprises: a switching circuit (31) having first transistors (32, 33) supplied with power supply potentials (VDD, VSS); correcting circuits (34, 36) connected between an input terminal (IN) inputted with an input signal and control terminals (gates) of the first transistors; capacitors (C2, C3) connected between the control terminals and the input terminal; diode-connected second transistors (35, 37) that are provided between nodes (N5, N6) between the capacitors and the control terminals and the power supply potentials and have the substantially same threshold voltage as the first transistors; and switches (SW2, SW3) connected in series with the second transistors.
    Type: Grant
    Filed: August 5, 2008
    Date of Patent: November 20, 2012
    Assignee: Semiconductor Energy Laboratory Co., Ltd.
    Inventor: Hajime Kimura
  • Publication number: 20120262218
    Abstract: A system includes at least two power semiconductor chips being connected in parallel and including each a gate terminal for switching the power semiconductor chip in a blocking-state by a first gate voltage and for switching the power semiconductor chip in a conducting-state by a second gate voltage. The system includes further a control device adapted for applying the first or the second gate voltage to the gate terminals of the at least two power semiconductor chips. The control device is adapted for applying a third gate voltage to the gate terminal of the at least one remaining power semiconductor chip when a power semiconductor chip fails, and that the third gate voltage is higher than the second gate voltage.
    Type: Application
    Filed: December 1, 2010
    Publication date: October 18, 2012
    Applicant: ABB TECHNOLOGY AG
    Inventors: Sven Klaka, Samuel Hartmann
  • Publication number: 20120194497
    Abstract: A gate driver includes a logic circuit for generating a plurality of buffer input signals and a modulation signal, a plurality of buffers each for generating a respective gate driving signal according to a corresponding one of the plurality of buffer input signals, and a switch module for controlling electrical connection between a first voltage source and the plurality of buffers. During a modulation period, the modulation signal indicates the switch module to break the electrical connection, and the plurality of buffer input signals are configured to short output terminals of the plurality of buffers so as to modulate the gate driving signals.
    Type: Application
    Filed: June 22, 2011
    Publication date: August 2, 2012
    Inventor: Tse-Hung Wu
  • Patent number: 7999601
    Abstract: A switch controller has a charge pump, a selector switch connected to the charge pump, and a pre-charge power supply input connectable to the input of the selector switch. For each of the output channels being controlled, a power control switch is connected to an output of the selector switch. In response to commands, output channels are enabled and disabled, causing corresponding actions in the power control switches. When an output channel is to be activated, the output channel is selected by the selector switch and the pre-charge power supply connected to the input of the selector switch. The charging is completed by the charge pump and the enabled status of the power control switch is maintained by the charge pump.
    Type: Grant
    Filed: April 1, 2005
    Date of Patent: August 16, 2011
    Assignee: Freescale Semiconductor, Inc.
    Inventors: David M. Schlueter, Cor H. Voorwinden
  • Publication number: 20100308890
    Abstract: A switch controller has a charge pump, a selector switch connected to the charge pump, and a pre-charge power supply input connectable to the input of the selector switch. For each of the output channels being controlled, a power control switch is connected to an output of the selector switch. In response to commands, output channels are enabled and disabled, causing corresponding actions in the power control switches. When an output channel is to be activated, the output channel is selected by the selector switch and the pre-charge power supply connected to the input of the selector switch. The charging is completed by the charge pump and the enabled status of the power control switch is maintained by the charge pump.
    Type: Application
    Filed: April 1, 2005
    Publication date: December 9, 2010
    Applicant: Freescale Semiconductor, Inc.
    Inventors: David M. Schlueter, Cor H. Voorwinden
  • Publication number: 20100045361
    Abstract: A power circuit. One embodiment provides a circuit for driving a power transistor having a control electrode and a load path. The circuit includes a driver circuit configured to change the power transistor to a completely on or off state with the aid of a control signal supplied to the control electrode. A series circuit includes a semiconductor switching element and a capacitor. The series circuit is connected in parallel with the load path and the capacitor provides a supply voltage for the driver circuit.
    Type: Application
    Filed: August 20, 2008
    Publication date: February 25, 2010
    Applicant: INFINEON TECHNOLOGIES AG
    Inventors: Peter Kanschat, Uwe Jansen, Gerald Deboy
  • Publication number: 20090322406
    Abstract: A semiconductor integrated circuit includes a core circuit, a power supply switch situated on a path providing a current to the core circuit and configured to control a state of current supply to the core circuit in response to a control signal applied to a control node, a clamp circuit configured to clamp a voltage of the control signal, and a switching circuit configured to control whether to enable or disable a clamp operation of the clamp circuit.
    Type: Application
    Filed: May 1, 2009
    Publication date: December 31, 2009
    Applicant: FUJITSU LIMITED
    Inventor: Kenichi Kawasaki
  • Publication number: 20090146724
    Abstract: Provided is a switching circuit for a millimeter waveband control circuit. The switching circuit for a millimeter waveband control circuit includes a switching cell disposed on a signal port path to match an interested frequency and including at least one transistor coupled vertically to an input/output transmission line and a plurality of ground via holes disposed symmetrically in an upper portion and a lower portion of the input/output transmission line; capacitors for stabilizing a bias of the switching cell; and bias pads coupled in parallel to the capacitor to control the switching cell.
    Type: Application
    Filed: June 13, 2008
    Publication date: June 11, 2009
    Applicant: ELECTRONICS & TELECOMMUNICATIONS RESEARCH INSTITUTE
    Inventors: Jae Kyoung Mun, Dong Young Kim, Jong Won Lim, Ho Kyun Ahn, Hae Cheon Kim, Hyun Kyu Yu
  • Patent number: 7453310
    Abstract: A switching circuit of the present invention can be advantageously used in an electronic control unit mounted on an automotive vehicle. The switching circuit is constituted by a pair of P-channel MOS-FETs connected in series between an input terminal and an output terminal. Sources of both MOS-FETs are connected to a common source junction and gates thereof are connected to a common gate junction. A Zener diode connected between the common source junction and the common gate junction is used for protecting the MOS-FETs. A resistor is connected in parallel to the Zener diode to bring the switching circuit to a non-conductive state when the gate voltage at the common gate junction becomes indefinite and a high voltage is supplied to the output terminal. In place of the resistor, an additional P-channel MOS-FET may be used in the switching circuit to bring the switching circuit to the non-conductive state when the voltage at the common gate junction becomes indefinite.
    Type: Grant
    Filed: August 8, 2006
    Date of Patent: November 18, 2008
    Assignee: DENSO CORPORATION
    Inventors: Kingo Ota, Shoichi Okuda
  • Publication number: 20080272823
    Abstract: A passgate circuit comprises a first depletion mode n-channel JFET, a depletion mode p-channel JFET, and a second depletion mode n-channel JFET. The first depletion mode n-channel JFET has a first terminal coupled to an input port, a second terminal that receives a first control signal, and a third terminal. The depletion mode p-channel JFET has a first terminal coupled to the third terminal of the first depletion mode n-channel JFET, a second terminal that receives a second control signal, and a third terminal. The second depletion mode n-channel JFET has a first terminal coupled to the third terminal of the depletion mode p-channel JFET, a second terminal that receives the first control signal, and a third terminal coupled to an output port.
    Type: Application
    Filed: May 3, 2007
    Publication date: November 6, 2008
    Inventors: Abhijit Ray, Damodar R. Thummalapally
  • Patent number: 7436237
    Abstract: A semiconductor switch includes a first semiconductor circuit having a nonlinear characteristic, and a second semiconductor circuit having a nonlinear characteristic. Each of the first semiconductor circuit and the second semiconductor circuit is configured to at least one of allow and interrupt transmission of a signal. The first semiconductor circuit reduces the nonlinear characteristic of the second semiconductor circuit and the second semiconductor circuit reduces the nonlinear characteristic of the first semiconductor circuit.
    Type: Grant
    Filed: May 27, 2005
    Date of Patent: October 14, 2008
    Assignee: Matsushita Electric Indsutrial Co., Ltd.
    Inventors: Masahiro Hikita, Manabu Yanagihara, Daisuke Ueda
  • Patent number: 7411318
    Abstract: Provided is a digital circuit (30) that comprises: a switching circuit (31) having first transistors (32, 33) supplied with power supply potentials (VDD, VSS): correcting circuits (34, 36) connected between an input terminal (IN) inputted with an input signal and control terminals (gates) of the first transistors: capacitors (C2, C3) connected between the control terminals and the input terminal: diode-connected second transistors (35, 37) that are provided between nodes (N5, N6) between the capacitors and the control terminals and the power supply potentials and have the substantially same threshold voltage as the first transistors; and switches (SW2, SW3) connected in series with the second transistors.
    Type: Grant
    Filed: December 22, 2003
    Date of Patent: August 12, 2008
    Assignee: Semiconductor Energy Laboratory Co., Ltd.
    Inventor: Hajime Kimura
  • Patent number: 7242238
    Abstract: A drive circuit for a voltage driven type semiconductor element, includes: an electrical charge discharge unit that discharges electrical charge from a gate terminal of a voltage driven type semiconductor element when the voltage driven type semiconductor element is turned OFF; and an electrical discharge control unit that detects a time variation of a collector voltage of the voltage driven type semiconductor element, and controls electric discharge by the electrical charge discharge unit according to the time variation of the collector voltage which has been detected.
    Type: Grant
    Filed: March 11, 2005
    Date of Patent: July 10, 2007
    Assignee: Nissan Motor Co., Ltd.
    Inventor: Kazuyuki Higashi
  • Patent number: 7173475
    Abstract: A signal transmission amplifier circuit has a transmission gate with an input coupled to an input signal. A cross coupled latch is coupled to an output of the transmission gate and has a signal output. A reference generating circuit is coupled to the cross coupled latch.
    Type: Grant
    Filed: March 10, 2004
    Date of Patent: February 6, 2007
    Assignee: Cypress Semiconductor Corp.
    Inventors: Gary Peter Moscaluk, John Eric Gross
  • Patent number: 6967519
    Abstract: A drive circuit for a power semiconductor device includes: a sampling signal generating circuit for detecting that an input control signal instructs OFF and outputting a sampling signal at the time instant of start of a Miller period of time of an IGBT; a gate voltage detecting circuit for detecting a Miller voltage of the IGBT at the timing when the sampling signal is inputted and outputting, when the Miller voltage is equal to or larger than a threshold, an over-current detection signal; and a gate voltage controlling circuit for controlling, in response to the over-current detection signal, a gate voltage of the IGBT in such a way that the IGBT is turned OFF at slower speed than in the normal state. Thus, it is possible to suppress a surge voltage which is generated when the IGBT is turned OFF during the flow of an over-current.
    Type: Grant
    Filed: January 16, 2003
    Date of Patent: November 22, 2005
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Yasushi Nakayama, Takeshi Ohi, Ryuichi Hashido
  • Patent number: 6731154
    Abstract: A method and apparatus for buffering a signal in a voltage island that is in standby or sleep mode. The apparatus uses a buffer(s) that are powered from a global power supply voltage that is always powered, and such buffer(s) are placed within the sleeping island itself. The sleeping island can be at the same or different voltage from the global voltage.
    Type: Grant
    Filed: May 1, 2002
    Date of Patent: May 4, 2004
    Assignee: International Business Machines Corporation
    Inventors: Thomas Richard Bednar, Scott Whitney Gould, David E. Lackey, Douglas Willard Stout, Paul Steven Zuchowski
  • Patent number: 6621321
    Abstract: An apparatus for conditioning an output waveform delivered from a testing device produces an output voltage that is the sum of a control voltage and an input voltage. To that end, the apparatus includes an input for receiving the input voltage, and an output capable of producing the output voltage. The output is coupled with the testing device. The apparatus further includes a voltage element coupled between the input and the output, and a switching element to alternatively charge and discharge the voltage element. The switching element controls the voltage element to change the control voltage between a first voltage and a second voltage. Consequently, the output voltage is the sum of the control voltage and the input voltage.
    Type: Grant
    Filed: June 20, 2001
    Date of Patent: September 16, 2003
    Assignee: Analog Devices, Inc.
    Inventors: Stephan Goldstein, Bruce Hecht
  • Patent number: 6597164
    Abstract: An on-chip test bus circuit for testing a plurality of circuits and an associated method. The test bus circuit consists of a test bus and a plurality of switching circuits which selectably provide electrical connections between the respective circuits and the test bus. The plurality of switching circuits are configured to transfer an electrical charge between a node disposed within each switching circuit not selected to provide an electrical connection and a respective charge source or sink. The charge source or sink may consist of a low-impedance, substantially noise-free DC voltage or signal source.
    Type: Grant
    Filed: September 12, 2001
    Date of Patent: July 22, 2003
    Assignee: Broadcom Corporation
    Inventor: Erlend Olson
  • Patent number: 5945851
    Abstract: A current source apparatus with bias switches, applied in digital-to-analog converters, is disclosed. The current compliance and settling time performances can be promoted via improving the structure of the bias circuit and making the MOS transistors operate in the saturation region, without increasing the dimensions of the MOS transistors.
    Type: Grant
    Filed: December 9, 1997
    Date of Patent: August 31, 1999
    Assignee: Industrial Technology Research Institute
    Inventors: Chien-Cheng Tu, Ching-Ching Chi
  • 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: 5675281
    Abstract: A method and circuit for preventing forward bias of a collector-substrate diode in an integrated circuit with a bipolar transistor where a load driven by the transistor may be offset from a reference voltage, such as circuit ground, by a varying voltage offset. The difference between the bipolar transistor collector voltage and the reference voltage is sensed, and the bipolar transistor base current is varied responsive to the sensed difference so that the base current is zero when the collector voltage is equal to the reference voltage, whereby the collector current will be less than .beta. times the base current when the emitter voltage is less than the reference voltage and the diode will not become forward biased.
    Type: Grant
    Filed: May 24, 1996
    Date of Patent: October 7, 1997
    Assignee: Harris Corporation
    Inventor: Thomas R. DeShazo, Jr.
  • Patent number: 5554944
    Abstract: In a sampling circuit including a first main terminal (P) and a series coupling of a hold capacitor (C2) and a sampling switch (S2) between the first main terminal (P) and a second main terminal (E), a parallel circuit (L2, R4) of a coil and a resistor (L2) is coupled in series with the sampling switch (S2) and the hold capacitor (C2), whereby the combination of the coil (L2), the resistor (R4) and the hold capacitor (C2) generate an excitation within a time period in which the sampling switch (S2) is conductive.
    Type: Grant
    Filed: June 28, 1995
    Date of Patent: September 10, 1996
    Assignee: U.S. Philips Corporation
    Inventors: Marinus C. W. Van Buul, Petrus G. M. Centen