Patents by Inventor Iwao Fukushi
Iwao Fukushi 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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Patent number: 8912780Abstract: A switching-control circuit to control switching of a transistor whose input electrode is applied with an input voltage, and turn off the transistor, when an output current from the transistor is greater than a reference current, includes: a reference-voltage-generating circuit to generate such a first-reference voltage that the reference current is reduced with reduction in an output voltage; a comparing circuit to compare a voltage corresponding to the output current with the first-reference voltage; and a driving circuit to turn on/off the transistor based on a feedback voltage corresponding to the output voltage and a second reference voltage corresponding to a target level so that the output voltage reaches the target level, when the comparing circuit determines that the output current is smaller than the reference current, and turn off the transistor when the comparing circuit determines that the output current is greater than the reference current.Type: GrantFiled: February 16, 2011Date of Patent: December 16, 2014Assignee: Semiconductor Components Industries, LLCInventors: Shuhei Kawai, Iwao Fukushi, Masahiro Maruki
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Patent number: 8415932Abstract: A switching control circuit includes an N-channel MOSFET having an input electrode applied with an input voltage and an output electrode connected to one end of an inductor and one end of a rectifying element. The other end of the inductor is connected to a first capacitor. A bootstrap circuit is configured to generate a bootstrap voltage on a second capacitor having one end connected to the output electrode of the N-channel MOSFET. The bootstrap voltage is required when the N-channel MOSFET is turned on. A driving circuit is configured to be applied with a driving voltage corresponding to the bootstrap voltage and turn on/off the N-channel MOSFET to generate an output voltage of a target level on the first capacitor. A clamping circuit is configured to clamp the driving voltage to be at a predetermined level or lower.Type: GrantFiled: December 16, 2009Date of Patent: April 9, 2013Assignees: Sanyo Semiconductor Co., Ltd., Semiconductor Components Industries, LLCInventors: Yosuke Kobayashi, Iwao Fukushi
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Patent number: 8179107Abstract: A power supply circuit comprising: a voltage generating circuit configured to generate an output voltage of a target level from an input voltage; an overcurrent protection circuit configured to control the voltage generating circuit so as to stop an output current, when a level of the output current generated at a time of generating the output voltage is greater than a reference level; and a reference-level change circuit configured to change the reference level in the overcurrent protection circuit to be at a second level higher than a first level from the first level for a predetermined period, when the overcurrent protection circuit detects that the level of the output current is greater than the reference level.Type: GrantFiled: January 15, 2009Date of Patent: May 15, 2012Assignees: Semiconductor Components Industries, LLC, Sanyo Semiconductor Co., Ltd.Inventor: Iwao Fukushi
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Publication number: 20110199145Abstract: A switching-control circuit to control switching of a transistor whose input electrode is applied with an input voltage, and turn off the transistor, when an output current from the transistor is greater than a reference current, includes: a reference-voltage-generating circuit to generate such a first-reference voltage that the reference current is reduced with reduction in an output voltage; a comparing circuit to compare a voltage corresponding to the output current with the first-reference voltage; and a driving circuit to turn on/off the transistor based on a feedback voltage corresponding to the output voltage and a second reference voltage corresponding to a target level so that the output voltage reaches the target level, when the comparing circuit determines that the output current is smaller than the reference current, and turn off the transistor when the comparing circuit determines that the output current is greater than the reference current.Type: ApplicationFiled: February 16, 2011Publication date: August 18, 2011Applicant: ON SEMICONDUCTOR TRADING, LTD.Inventors: Shuhei Kawai, Iwao Fukushi, Masahiro Maruki
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Publication number: 20110127974Abstract: A switching control circuit includes: a drive circuit configured to turn on/off a transistor according to a duty ratio of a drive signal so as to generate an output voltage of a target level from an input voltage, the transistor configured to be applied with the input voltage at an input electrode thereof; and a drive signal generation circuit configured to change the duty ratio of the drive signal based on a reference voltage and a feedback voltage corresponding to the output voltage, to generate the drive signal having the duty ratio which is changed so that the feedback voltage becomes equal in level to the reference voltage, and which is changed so that the output voltage is reduced with a rise in temperature.Type: ApplicationFiled: November 29, 2010Publication date: June 2, 2011Applicants: SANYO ELECTRIC CO., LTD., SANYO SEMICONDUCTOR CO., LTD.Inventor: Iwao Fukushi
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Patent number: 7940507Abstract: The switching control circuit comprises a switching control signal generation circuit that detects a change in ripples of the output voltage and-generates a switching control signal for the on/off control of the switching element to make the output voltage follow the target level; an overcurrent state detection circuit that generates a state signal indicating whether the output current is in an overcurrent state where the output current is equal to or greater than a predetermined current; and a delay circuit that delays the state signal for a same predetermined delay time at both of the times when the output current exceeds the predetermined current and when the output current falls below the predetermined current.Type: GrantFiled: March 29, 2010Date of Patent: May 10, 2011Assignees: Sanyo Electric Co., Ltd., Murata Manufacturing Co., Ltd.Inventors: Iwao Fukushi, Tomoaki Nishi, Takashi Noma
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Patent number: 7782024Abstract: A switching control circuit comprises: an error amplifying circuit configured to output an error voltage obtained by amplifying an error between a feedback voltage corresponding to an output voltage and a lower voltage selected out of a first reference voltage increasing with time passage and a second reference voltage used as a reference for a target level; a comparison circuit configured to output a comparison signal obtained by comparing the feedback voltage with the error voltage output from the error amplifying circuit; and a drive circuit configured to output first and second control signals for controlling first and second transistors, respectively, in order to turn the output voltage to the target level by complementarily turning on and off the first and second transistors, after the error voltage exceeds the feedback voltage, based on the comparison signal output from the comparison circuit.Type: GrantFiled: April 4, 2007Date of Patent: August 24, 2010Assignees: Sanyo Electric Co., Ltd., Murata Manufacturing Co., Ltd.Inventors: Iwao Fukushi, Masahiro Maruki, Takashi Noma
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Publication number: 20100194364Abstract: A switching-power-supply control circuit comprising: a first control circuit to operate a first transistor applied with an input voltage at an input electrode thereof and a second transistor connected in series to the first transistor, based on a first feedback voltage and first reference voltage, the first feedback voltage corresponding to an output voltage obtained through a connection point between the first and second transistors; and a second control circuit to allow the first control circuit to turn on/off the first and second transistors in a complementary manner so that the first feedback voltage becomes equal to the first reference voltage, when a second feedback voltage rising with rise of the output voltage is lower than a second reference voltage, and allow the first control circuit to turn off the second transistor, when the second feedback voltage is higher than the second reference voltage, according to the output voltage.Type: ApplicationFiled: January 26, 2010Publication date: August 5, 2010Applicants: Sanyo Electric Co., Ltd., Sanyo Semiconductor Co., Ltd.Inventors: Iwao Fukushi, Shuhei Kawai
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Publication number: 20100181984Abstract: The switching control circuit comprises a switching control signal generation circuit that detects a change in ripples of the output voltage and-generates a switching control signal for the on/off control of the switching element to make the output voltage follow the target level; an overcurrent state detection circuit that generates a state signal indicating whether the output current is in an overcurrent state where the output current is equal to or greater than a predetermined current; and a delay circuit that delays the state signal for a same predetermined delay time at both of the times when the output current exceeds the predetermined current and when the output current falls below the predetermined current.Type: ApplicationFiled: March 29, 2010Publication date: July 22, 2010Applicants: Sanyo Electric Co., Ltd., Murata Manufacturing Co., Ltd.Inventors: Iwao Fukushi, Tomoaki Nishi, Takashi Noma
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Patent number: 7755874Abstract: A self-excited DC-DC converter includes a switching element that chops an input voltage; a smoothing circuit that smoothes the chopped voltage to generate an output voltage; and a switching control circuit. The switching control circuit includes a switching control signal generation circuit that generates a switching control signal for the on/off control of the switching element by comparing a feedback voltage of the output voltage and a comparison voltage; an output correction circuit that adjusts the comparison voltage according to an error between the feedback voltage and the reference voltage and, when the output current is in the overcurrent state, reduces the level of the comparison voltage; an overcurrent protection signal generation circuit that, when the output current is in an overcurrent state, generates an overcurrent protection signal for turning off the switching element regardless of the switching control signal; and a delay circuit that delays the overcurrent protection signal.Type: GrantFiled: January 17, 2008Date of Patent: July 13, 2010Assignees: Sanyo Electric Co., Ltd., Murata Manufacturing Co., Ltd.Inventors: Iwao Fukushi, Tomoaki Nishi, Takashi Noma
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Publication number: 20100156372Abstract: A switching control circuit includes an N-channel MOSFET having an input electrode applied with an input voltage and an output electrode connected to one end of an inductor and one end of a rectifying element. The other end of the inductor is connected to a first capacitor. A bootstrap circuit is configured to generate a bootstrap voltage on a second capacitor having one end connected to the output electrode of the N-channel MOSFET. The bootstrap voltage is required when the N-channel MOSFET is turned on. A driving circuit is configured to be applied with a driving voltage corresponding to the bootstrap voltage and turn on/off the N-channel MOSFET to generate an output voltage of a target level on the first capacitor. A clamping circuit is configured to clamp the driving voltage to be at a predetermined level or lower.Type: ApplicationFiled: December 16, 2009Publication date: June 24, 2010Applicants: SANYO ELECTRIC CO., LTD., SANYO SEMICONDUCTOR CO., LTD.Inventors: Yosuke Kobayashi, Iwao Fukushi
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Publication number: 20090322302Abstract: A power supply circuit comprising: a voltage generating circuit configured to generate an output voltage of a target level from an input voltage; an overcurrent protection circuit configured to control the voltage generating circuit so as to stop an output current, when a level of the output current generated at a time of generating the output voltage is greater than a reference level; and a reference-level change circuit configured to change the reference level in the overcurrent protection circuit to be at a second level higher than a first level from the first level for a predetermined period, when the overcurrent protection circuit detects that the level of the output current is greater than the reference level.Type: ApplicationFiled: January 15, 2009Publication date: December 31, 2009Applicants: Sanyo Electric Co., Ltd., Sanyo Semiconductor Co., Ltd.Inventor: Iwao Fukushi
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Publication number: 20090039851Abstract: A switching control circuit comprises: an error amplifying circuit configured to output an error voltage obtained by amplifying an error between a feedback voltage corresponding to an output voltage and a lower voltage selected out of a first reference voltage increasing with time passage and a second reference voltage used as a reference for a target level; a comparison circuit configured to output a comparison signal obtained by comparing the feedback voltage with the error voltage output from the error amplifying circuit; and a drive circuit configured to output first and second control signals for controlling first and second transistors, respectively, in order to turn the output voltage to the target level by complementarily turning on and off the first and second transistors, after the error voltage exceeds the feedback voltage, based on the comparison signal output from the comparison circuit.Type: ApplicationFiled: April 4, 2007Publication date: February 12, 2009Applicants: Sanyo Electric Co., Ltd., Murata Manufacturing Co., Ltd.Inventors: Iwao Fukushi, Masahiro Maruki, Takashi Noma
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Publication number: 20080136394Abstract: A self-excited DC-DC converter comprises a switching element that chops a direct-current input voltage; a smoothing circuit that smoothes the chopped voltage to generate a DC output voltage; a switching control signal generation circuit that generates a switching control signal for the on/off control of the switching element by comparing a feedback voltage of the output voltage and a comparison voltage; an output correction circuit that adjusts the comparison voltage according to an error between the feedback voltage and the reference voltage and, when the output current is in the overcurrent state, reduces the level of the comparison voltage; an overcurrent protection signal generation circuit that, when the output current is in an overcurrent state, generates an overcurrent protection signal for turning off the switching element regardless of the switching control signal; and a delay circuit that delays the overcurrent protection signal. Also, a switching control circuit is provided therein.Type: ApplicationFiled: January 17, 2008Publication date: June 12, 2008Applicants: Sanyo Electric Co., Ltd., Murata Manufacturing Co., Ltd.Inventors: Iwao Fukushi, Tomoaki Nishi, Takashi Noma
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Patent number: 7379284Abstract: A self-excited DC-DC converter comprises a switching element that chops a direct-current input voltage; a smoothing circuit that smoothes the chopped voltage to generate a DC output voltage; a switching control signal generation circuit that generates a switching control signal for the on/off control of the switching element by comparing a feedback voltage of the output voltage and a comparison voltage; an output correction circuit that adjusts the comparison voltage according to an error between the feedback voltage and the reference voltage and, when the output current is in the overcurrent state, reduces the level of the comparison voltage; an overcurrent protection signal generation circuit that, when the output current is in an overcurrent state, generates an overcurrent protection signal for turning off the switching element regardless of the switching control signal; and a delay circuit that delays the overcurrent protection signal. Also, a switching control circuit is provided therein.Type: GrantFiled: June 23, 2006Date of Patent: May 27, 2008Assignees: Sanyo Electric Co., Ltd., Murata Manufacturing Co., Ltd.Inventors: Iwao Fukushi, Tomoaki Nishi, Takashi Noma
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Patent number: 7224192Abstract: A voltage detection circuit, comprises a constant-current circuit, a current mirror circuit operated by the constant-current circuit, at least one diode-connected first transistor disposed between an output of the current mirror circuit and a detected voltage, and an output circuit outputting one logic voltage in response to a turn-on of the first transistor when the detected voltage is a predetermined voltage or higher, and outputting the other logic voltage in response to a turn-off of the first transistor when the detected voltage is lower than the predetermined voltage.Type: GrantFiled: October 14, 2005Date of Patent: May 29, 2007Assignee: Sanyo Electric Co., Ltd.Inventors: Iwao Fukushi, Noriaki Okada
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Publication number: 20060290333Abstract: A self-excited DC-DC converter comprises a switching element that chops a direct-current input voltage; a smoothing circuit that smoothes the chopped voltage to generate a DC output voltage; a switching control signal generation circuit that generates a switching control signal for the on/off control of the switching element by comparing a feedback voltage of the output voltage and a comparison voltage; an output correction circuit that adjusts the comparison voltage according to an error between the feedback voltage and the reference voltage and, when the output current is in the overcurrent state, reduces the level of the comparison voltage; an overcurrent protection signal generation circuit that, when the output current is in an overcurrent state, generates an overcurrent protection signal for turning off the switching element regardless of the switching control signal; and a delay circuit that delays the overcurrent protection signal. Also, a switching control circuit is provided therein.Type: ApplicationFiled: June 23, 2006Publication date: December 28, 2006Applicants: Sanyo Electric Co., Ltd., Murata Manufacturing Co., Ltd.Inventors: Iwao Fukushi, Tomoaki Nishi, Takashi Noma
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Publication number: 20060082395Abstract: A voltage detection circuit, comprises a constant-current circuit, a current mirror circuit operated by the constant-current circuit, at least one diode-connected first transistor disposed between an output of the current mirror circuit and a detected voltage, and an output circuit outputting one logic voltage in response to a turn-on of the first transistor when the detected voltage is a predetermined voltage or higher, and outputting the other logic voltage in response to a turn-off of the first transistor when the detected voltage is lower than the predetermined voltage.Type: ApplicationFiled: October 14, 2005Publication date: April 20, 2006Applicant: Sanyo Electric Co., Ltd.Inventors: Iwao Fukushi, Noriaki Okada