Patents by Inventor Toshio Nagasawa
Toshio Nagasawa has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).
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Publication number: 20120049337Abstract: A non-insulated DC-DC converter has a power MOSFET for a highside switch and a power MOS•ET for a lowside switch. In the non-insulated DC-DC converter, the power MOS•ET for the highside switch and the power MOS•ET for the lowside switch, driver circuits that control operations of these elements, respectively, and a Schottky barrier diode connected in parallel with the power MOS•ET for the lowside switch are respectively formed in four different semiconductor chips. These four semiconductor chips are housed in one package. The semiconductor chips are mounted over the same die pad. The semiconductor chips are disposed so as to approach each other.Type: ApplicationFiled: November 10, 2011Publication date: March 1, 2012Inventors: Tomoaki UNO, Masaki Shiraishi, Nobuyoshi Matsuura, Toshio Nagasawa
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Patent number: 8076767Abstract: A non-insulated DC-DC converter has a power MOS-FET for a highside switch and a power MOS-FET for a lowside switch. In the non-insulated DC-DC converter, the power MOS-FET for the highside switch and the power MOS-FET for the lowside switch, driver circuits that control operations of these elements, respectively, and a Schottky barrier diode connected in parallel with the power MOS-FET for the lowside switch are respectively formed in four different semiconductor chips. These four semiconductor chips are housed in one package. The semiconductor chips are mounted over the same die pad. The semiconductor chips are disposed so as to approach each other.Type: GrantFiled: October 26, 2010Date of Patent: December 13, 2011Assignee: Renesas Electronics CorporationInventors: Tomoaki Uno, Masaki Shiraishi, Nobuyoshi Matsuura, Toshio Nagasawa
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Patent number: 8072246Abstract: A switching power supply device performs a stable operation with fast response for a semiconductor integrated circuit device. A capacitor is provided between the output side of an inductor and a ground potential. A first power MOSFET supplies an electric current from an input voltage to the input side of the inductor. A second power MOSFET turned on when the first power MOSFET is off allows the input side of the inductor to be of a predetermined potential. A first feedback signal corresponding to an output voltage obtained from the output side of the inductor and a second feedback signal corresponding to an electric current flowed to the first power MOSFET are used to form a PWM signal. The first power MOSFET has plural cells of a vertical type MOS-construction.Type: GrantFiled: November 19, 2010Date of Patent: December 6, 2011Assignee: Renesas Electronics CorporationInventors: Toshio Nagasawa, Ryotaro Kudo
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Patent number: 8063620Abstract: The present invention provides a switching power source and a semiconductor integrated circuit which realize an acquisition a sufficient driving voltage of a high-potential side switching element M1 even when a power source voltage VDD is low.Type: GrantFiled: February 9, 2011Date of Patent: November 22, 2011Assignee: Renesas Electronics CorporationInventors: Kyoichi Hosokawa, Ryotaro Kudo, Toshio Nagasawa, Koji Tateno
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Patent number: 7986133Abstract: To provide a power supply unit capable of realizing a multiphase power supply at low cost. For example, each of a plurality of semiconductor devices DEV[1]-DEV[n] comprises a trigger input terminal TRG_IN, a trigger output terminal TRG_OUT, and a timer circuit TM that delays a pulse signal input from TRG_IN and outputs it to TRG_OUT. DEV[1]-DEV[n] are mutually coupled in a ring shape by its own TRG_IN being coupled to TRG_OUT of one semiconductor device other than itself. Each of DEV[1]-DEV[n] performs switching operation by using the pulse signal from TRG_IN as a starting point, and feeds a current into an inductor L corresponding to itself. Moreover, DEV[1] generates the above-described pulse signal only once during startup by a start trigger terminal ST being set to a ground voltage GND, for example.Type: GrantFiled: July 12, 2010Date of Patent: July 26, 2011Assignee: Renesas Electronics CorporationInventors: Ryotaro Kudo, Toshio Nagasawa
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Publication number: 20110169471Abstract: A multi-phase power source device capable of easily changing the number of phases is realized. For example, a plurality of drive units POL[1]-POL[4] corresponding to the number of phases are provided, wherein each POL[n] receives a phase input signal PHI[n] serving as a pulse signal, and generates a phase output signal PHO[n] by delaying PHI[n] by a predetermined cycles of a clock signal CLK. PHI[n] and PHO[n] of each POL[n] are coupled in a ring, wherein each POL[n] performs a switching operation with PHI[n] or PHO[n] as a starting point. In this case, each POL[n] charges and discharges a capacitor Cct commonly coupled to each POL[n] with an equal current, and a frequency of CLK is determined based on this charge and discharge rate. That is, if the number of phases increases n times, the frequency of CLK will be automatically controlled to n times.Type: ApplicationFiled: December 29, 2010Publication date: July 14, 2011Applicant: RENESAS ELECTRONICS CORPORATIONInventor: Toshio NAGASAWA
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Publication number: 20110127975Abstract: The present invention provides a switching power source and a semiconductor integrated circuit which realize an acquisition a sufficient driving voltage of a high-potential side switching element M1 even when a power source voltage VDD is low.Type: ApplicationFiled: February 9, 2011Publication date: June 2, 2011Inventors: KYOICHI HOSOKAWA, Ryotaro Kudo, Toshio Nagasawa, Koji Tateno
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Publication number: 20110062927Abstract: A switching power supply device performs a stable operation with fast response for a semiconductor integrated circuit device. A capacitor is provided between the output side of an inductor and a ground potential. A first power MOSFET supplies an electric current from an input voltage to the input side of the inductor. A second power MOSFET turned on when the first power MOSFET is off allows the input side of the inductor to be of a predetermined potential. A first feedback signal corresponding to an output voltage obtained from the output side of the inductor and a second feedback signal corresponding to an electric current flowed to the first power MOSFET are used to form a PWM signal. The first power MOSFET has plural cells of a vertical type MOS-construction.Type: ApplicationFiled: November 19, 2010Publication date: March 17, 2011Applicant: RENESAS TECHNOLOGY CORPORATIONInventors: Toshio NAGASAWA, Ryotaro KUDO
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Patent number: 7902799Abstract: The present invention provides a switching power source and a semiconductor integrated circuit which realize an acquisition a sufficient driving voltage of a high-potential side switching element M1 even when a power source voltage VDD is low.Type: GrantFiled: March 13, 2009Date of Patent: March 8, 2011Assignee: Renesas Electronics CorporationInventors: Kyoichi Hosokawa, Ryotaro Kudo, Toshio Nagasawa, Koji Tateno
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Publication number: 20110037449Abstract: A non-insulated DC-DC converter has a power MOS-FET for a highside switch and a power MOS-FET for a lowside switch. In the non-insulated DC-DC converter, the power MOS-FET for the highside switch and the power MOS-FET for the lowside switch, driver circuits that control operations of these elements, respectively, and a Schottky barrier diode connected in parallel with the power MOS-FET for the lowside switch are respectively formed in four different semiconductor chips. These four semiconductor chips are housed in one package. The semiconductor chips are mounted over the same die pad. The semiconductor chips are disposed so as to approach each other.Type: ApplicationFiled: October 26, 2010Publication date: February 17, 2011Inventors: Tomoaki UNO, Masaki Shiraishi, Nobuyoshi Matsuura, Toshio Nagasawa
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Patent number: 7863756Abstract: A non-insulated DC-DC converter has a power MOS•FET for a highside switch and a power MOS•FET for a lowside switch. In the non-insulated DC-DC converter, the power MOS•FET for the highside switch and the power MOS•FET for the lowside switch, driver circuits that control operations of these elements, respectively, and a Schottky barrier diode connected in parallel with the power MOS•FET for the lowside switch are respectively formed in four different semiconductor chips. These four semiconductor chips are housed in one package. The semiconductor chips are mounted over the same die pad. The semiconductor chips are disposed so as to approach each other.Type: GrantFiled: September 24, 2008Date of Patent: January 4, 2011Assignee: Renesas Electronics CorporationInventors: Tomoaki Uno, Masaki Shiraishi, Nobuyoshi Matsuura, Toshio Nagasawa
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Patent number: 7859326Abstract: A switching power supply device performs a stable operation with fast response for a semiconductor integrated circuit device. A capacitor is provided between the output side of an inductor and a ground potential. A first power MOSFET supplies an electric current from an input voltage to the input side of the inductor. A second power MOSFET turned on when the first power MOSFET is off allows the input side of the inductor to be of a predetermined potential. A first feedback signal corresponding to an output voltage obtained from the output side of the inductor and a second feedback signal corresponding to an electric current flowed to the first power MOSFET are used to form a PWM signal. The first power MOSFET has plural cells of a vertical type MOS-construction.Type: GrantFiled: July 10, 2008Date of Patent: December 28, 2010Assignee: Renesas Electronics CorporationInventors: Toshio Nagasawa, Ryotaro Kudo
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Publication number: 20100277143Abstract: To provide a power supply unit capable of realizing a multiphase power supply at low cost. For example, each of a plurality of semiconductor devices DEV[1]-DEV[n] comprises a trigger input terminal TRG_IN, a trigger output terminal TRG_OUT, and a timer circuit TM that delays a pulse signal input from TRG_IN and outputs it to TRG_OUT. DEV[1]-DEV[n] are mutually coupled in a ring shape by its own TRG_IN being coupled to TRG_OUT of one semiconductor device other than itself. Each of DEV[1]-DEV[n] performs switching operation by using the pulse signal from TRG_IN as a starting point, and feeds a current into an inductor L corresponding to itself. Moreover, DEV[1] generates the above-described pulse signal only once during startup by a start trigger terminal ST being set to a ground voltage GND, for example.Type: ApplicationFiled: July 12, 2010Publication date: November 4, 2010Applicant: RENESAS TECHNOLOGY CORP.Inventors: Ryotaro Kudo, Toshio Nagasawa
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Patent number: 7777462Abstract: To provide a power supply unit capable of realizing a multiphase power supply at low cost. For example, each of a plurality of semiconductor devices DEV[1]-DEV[n] comprises a trigger input terminal TRG_IN, a trigger output terminal TRG_OUT, and a timer circuit TM that delays a pulse signal input from TRG_IN and outputs it to TRG_OUT. DEV[1]-DEV[n] are mutually coupled in a ring shape by its own TRG_IN being coupled to TRG_OUT of one semiconductor device other than itself. Each of DEV[1]-DEV[n] performs switching operation by using the pulse signal from TRG_IN as a starting point, and feeds a current into an inductor L corresponding to itself. Moreover, DEV[1] generates the above-described pulse signal only once during startup by a start trigger terminal ST being set to a ground voltage GND, for example.Type: GrantFiled: December 15, 2008Date of Patent: August 17, 2010Assignee: Renesas Technology Corp.Inventors: Ryotaro Kudo, Toshio Nagasawa
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Publication number: 20090267587Abstract: In a driver circuit constructing a switching power supply device that switches power transistors passing a current through a coil by a PWM mode, a current detection transistor, which is smaller in size than the low-potential side power transistor, and a current detection resistor are provided in parallel to the low-potential side power transistor. The same control voltage as the power transistor is applied to the control terminal of the current detection transistor. An operational amplifier is formed, that has the potential of the connection node between the current detection transistor and the current detection resistor applied to its inverse input terminal and a feedback loop, so as to make a pair of input terminals of the operational amplifier be at the same potential. A signal produced by the current detection resistor is thus outputted as a current detection signal.Type: ApplicationFiled: June 18, 2009Publication date: October 29, 2009Applicant: RENEAS TECHNOLOGY CORP.Inventors: Koji Tateno, Ryotaro Kudo, Shin Chiba, Kyoichi Hosokawa, Toshio Nagasawa
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Publication number: 20090224732Abstract: To provide a power supply unit capable of realizing a multiphase power supply at low cost. For example, each of a plurality of semiconductor devices DEV[1]-DEV[n] comprises a trigger input terminal TRG_IN, a trigger output terminal TRG_OUT, and a timer circuit TM that delays a pulse signal input from TRG_IN and outputs it to TRG_OUT. DEV[1]-DEV[n] are mutually coupled in a ring shape by its own TRG_IN being coupled to TRG_OUT of one semiconductor device other than itself. Each of DEV[1]-DEV[n] performs switching operation by using the pulse signal from TRG_IN as a starting point, and feeds a current into an inductor L corresponding to itself. Moreover, DEV[1] generates the above-described pulse signal only once during startup by a start trigger terminal ST being set to a ground voltage GND, for example.Type: ApplicationFiled: December 15, 2008Publication date: September 10, 2009Inventors: Ryotaro Kudo, Toshio Nagasawa
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Publication number: 20090179620Abstract: The present invention provides a switching power source and a semiconductor integrated circuit which realize an acquisition a sufficient driving voltage of a high-potential side switching element M1 even when a power source voltage VDD is low.Type: ApplicationFiled: March 13, 2009Publication date: July 16, 2009Inventors: KYOICHI HOSOKAWA, Ryotaro Kudo, Toshio Nagasawa, Koji Tateno
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Patent number: 7550959Abstract: In a driver circuit constructing a switching power supply device that switches power transistors passing a current through a coil by a PWM mode, a current detection transistor, which is smaller in size than the low-potential side power transistor, and a current detection resistor are provided in parallel to the low-potential side power transistor. The same control voltage as the power transistor is applied to the control terminal of the current detection transistor. An operational amplifier is formed, that has the potential of the connection node between the current detection transistor and the current detection resistor applied to its inverse input terminal and a feedback loop, so as to make a pair of input terminals of the operational amplifier be at the same potential. A signal produced by the current detection resistor is thus outputted as a current detection signal.Type: GrantFiled: January 22, 2008Date of Patent: June 23, 2009Assignee: Renesas Technology Corp.Inventors: Koji Tateno, Ryotaro Kudo, Shin Chiba, Kyoichi Hosokawa, Toshio Nagasawa
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Patent number: 7514908Abstract: The present invention provides a switching power source and a semiconductor integrated circuit which realize an acquisition a sufficient driving voltage of a high-potential side switching element M1 even when a power source voltage VDD is low.Type: GrantFiled: January 14, 2005Date of Patent: April 7, 2009Assignee: Renesas Technology Corp.Inventors: Kyoichi Hosokawa, Ryotaro Kudo, Toshio Nagasawa, Koji Tateno
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Publication number: 20090026544Abstract: A non-insulated DC-DC converter has a power MOS•FET for a highside switch and a power MOS•FET for a lowside switch. In the non-insulated DC-DC converter, the power MOS•FET for the highside switch and the power MOS•FET for the lowside switch, driver circuits that control operations of these elements, respectively, and a Schottky barrier diode connected in parallel with the power MOS•FET for the lowside switch are respectively formed in four different semiconductor chips. These four semiconductor chips are housed in one package. The semiconductor chips are mounted over the same die pad. The semiconductor chips are disposed so as to approach each other.Type: ApplicationFiled: September 24, 2008Publication date: January 29, 2009Inventors: Tomoaki Uno, Masaki Shiraishi, Nobuyoshi Matsuura, Toshio Nagasawa