Patents by Inventor Kiyotaka Umemoto
Kiyotaka Umemoto 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: 20160226487Abstract: A semiconductor device includes: a first external terminal which receives an input voltage; a second external terminal which outputs a switch voltage; a third external terminal connected to a first ground; a fourth external terminal connected to a second ground; a first internal switch element formed on a semiconductor substrate to be connected between the first and second external terminals; a second internal switch element formed on the semiconductor substrate to be connected between the second external terminal and the third external terminal; and a control circuit connected to the fourth external terminal to drive at least one of the first internal switch element and the second internal switch element. The semiconductor substrate is electrically connected with the third external terminal rather than the fourth external terminal, and parasitic elements accompanied between the semiconductor substrate and each of the first internal switch element and the second internal switch element.Type: ApplicationFiled: January 29, 2016Publication date: August 4, 2016Inventor: Kiyotaka Umemoto
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Publication number: 20160224049Abstract: A constant voltage generating circuit includes an ED-type reference voltage supply that generates a predetermined constant voltage by using a first transistor of depletion-type and a second transistor of enhancement-type that are connected in series between a power supply terminal and a ground terminal, and a third transistor a source of which is connected to an output terminal for the constant voltage, a drain of which is connected to the power supply terminal or the ground terminal, and a gate of which is connected to a connection node between the first transistor and the second transistor.Type: ApplicationFiled: February 1, 2016Publication date: August 4, 2016Inventors: Kiyotaka Umemoto, Genki Tsuruyama
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Publication number: 20150243585Abstract: A semiconductor device includes a semiconductor chip including a semiconductor substrate, an element formed in an element forming region of the semiconductor substrate, and a through-via penetrating across a front surface and a rear surface of the semiconductor substrate while avoiding the element forming region of the semiconductor substrate to form a conductive path between the front surface and the rear surface; a circuit component mounted on a circuit component connection surface at the same side as the front surface of the semiconductor substrate of the semiconductor chip; and an external connection members formed on the rear surface of the semiconductor substrate.Type: ApplicationFiled: February 18, 2015Publication date: August 27, 2015Inventor: Kiyotaka Umemoto
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Publication number: 20140291679Abstract: A semiconductor device disclosed in the present specification comprises: a semiconductor chip, a package that incorporates the semiconductor chip, and a plurality of lower-surface pads disposed on a lower surface of the package, a plurality of upper-surface pads disposed on an upper surface of the package, wherein the plurality of upper-surface pads include a plurality of monitor pads each of which is connected to each of all the lower-surface pads.Type: ApplicationFiled: March 27, 2014Publication date: October 2, 2014Applicant: Rohm Co., Ltd.Inventor: Kiyotaka Umemoto
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Patent number: 8558529Abstract: An output monitoring comparator outputs an ON signal when an output voltage becomes lower than a reference voltage. A pulse modulator generates a pulse signal at a predetermined level, an ON time-period from when the ON signal is outputted. A driver circuit alternately turns ON, after a dead time, a switching transistor and a synchronous rectification transistor, based on the pulse signal. A light load mode detector compares a switching voltage at a connection point of the switching transistor and the synchronous rectification transistor, and ground potential, and at timing at which the ON signal is outputted from the output monitoring comparator, when the switching voltage is higher than the ground potential, nullifies the ON signal.Type: GrantFiled: December 20, 2011Date of Patent: October 15, 2013Assignee: Rohm Co., Ltd.Inventors: Masaru Sakai, Kiyotaka Umemoto
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Publication number: 20120091983Abstract: An output monitoring comparator outputs an ON signal when an output voltage becomes lower than a reference voltage. A pulse modulator generates a pulse signal at a predetermined level, an ON time-period from when the ON signal is outputted. A driver circuit alternately turns ON, after a dead time, a switching transistor and a synchronous rectification transistor, based on the pulse signal. A light load mode detector compares a switching voltage at a connection point of the switching transistor and the synchronous rectification transistor, and ground potential, and at timing at which the ON signal is outputted from the output monitoring comparator, when the switching voltage is higher than the ground potential, nullifies the ON signal.Type: ApplicationFiled: December 20, 2011Publication date: April 19, 2012Applicant: ROHM CO., LTD.Inventors: Masaru SAKAI, Kiyotaka UMEMOTO
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Publication number: 20120049821Abstract: The switching regulator according to the present invention comprises an oscillation circuit for generating a clock signal having a predetermined oscillation frequency; and a switching signal generation circuit for generating a switching signal for driving a switching element connected to an output circuit; wherein the switching signal generation circuit varies the ON time of the switching signal so that the frequency of the switching signal approaches the frequency of the clock signal; and varies the timing at which the switching signal is ON so that an output voltage outputted from the output circuit approaches a predetermined reference voltage.Type: ApplicationFiled: August 18, 2011Publication date: March 1, 2012Applicant: Rohm Co., Ltd.Inventors: Shingo Hashiguchi, Hideo Hara, Kiyotaka Umemoto
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Patent number: 8111051Abstract: An output monitoring comparator outputs an ON signal when an output voltage becomes lower than a reference voltage. A pulse modulator generates a pulse signal at a predetermined level, an ON time-period from when the ON signal is outputted. A driver circuit alternately turns ON, after a dead time, a switching transistor and a synchronous rectification transistor, based on the pulse signal. A light load mode detector compares a switching voltage at a connection point of the switching transistor and the synchronous rectification transistor, and ground potential, and at timing at which the ON signal is outputted from the output monitoring comparator, when the switching voltage is higher than the ground potential, nullifies the ON signal.Type: GrantFiled: April 20, 2006Date of Patent: February 7, 2012Assignee: Rohm Co., Ltd.Inventors: Masaru Sakai, Kiyotaka Umemoto
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Patent number: 8072201Abstract: In a power supply apparatus that is so configured as to produce from an input voltage an output voltage Vo within a predetermined permissible variation range, the output voltage Vo is so controlled as to decrease within the permissible variation range as the output current Io increases. This configuration offers an output voltage with an improved transient characteristic against an abrupt variation in the output current and simultaneously permits reduction of the power consumed when the output current increases.Type: GrantFiled: January 8, 2010Date of Patent: December 6, 2011Assignee: Rohm Co., Ltd.Inventors: Kiyotaka Umemoto, Ko Takemura
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Publication number: 20100156366Abstract: An output monitoring comparator outputs an ON signal when an output voltage becomes lower than a reference voltage. A pulse modulator generates a pulse signal at a predetermined level, an ON time-period from when the ON signal is outputted. A driver circuit alternately turns ON, after a dead time, a switching transistor and a synchronous rectification transistor, based on the pulse signal. A light load mode detector compares a switching voltage at a connection point of the switching transistor and the synchronous rectification transistor, and ground potential, and at timing at which the ON signal is outputted from the output monitoring comparator, when the switching voltage is higher than the ground potential, nullifies the ON signal.Type: ApplicationFiled: April 20, 2006Publication date: June 24, 2010Applicant: ROHM CO., LTD.Inventors: Masaru Sakai, Kiyotaka Umemoto
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Publication number: 20100109629Abstract: In a power supply apparatus that is so configured as to produce from an input voltage an output voltage Vo within a predetermined permissible variation range, the output voltage Vo is so controlled as to decrease within the permissible variation range as the output current Io increases.Type: ApplicationFiled: January 8, 2010Publication date: May 6, 2010Applicant: ROHM CO., LTD.Inventors: Kiyotaka UMEMOTO, Ko Takemura
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Patent number: 7663355Abstract: In a power supply apparatus that is so configured as to produce from an input voltage an output voltage Vo within a predetermined permissible variation range, the output voltage Vo is so controlled as to decrease within the permissible variation range as the output current Io increases. This configuration offers an output voltage with an improved transient characteristic against an abrupt variation in the output current and simultaneously permits reduction of the power consumed when the output current increases.Type: GrantFiled: December 30, 2008Date of Patent: February 16, 2010Assignee: Rohm Co., Ltd.Inventors: Kiyotaka Umemoto, Ko Takemura
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Patent number: 7612545Abstract: A DC/DC converter includes a switching element which is opened and closed to supply power from an input power supply Vcc through a coil to an output terminal, which is connected to a load, and to adjust the voltage at the output terminal. The DC/DC converter also includes a coil current detection resistor arranged to detect a coil current, a smoothing capacitor connected to the load side of the coil current detection resistor and arranged to smooth the voltage at the output terminal, a reference current value control circuit arranged to detect the voltage on the coil side of the coil current detection resistor to control a reference current value of the coil current, a clock generator arranged to generate a reference clock, and a feedback circuit arranged to close the switching element in synchrony with the reference clock and to open the switching element when the coil current exceeds the reference current value.Type: GrantFiled: November 11, 2004Date of Patent: November 3, 2009Assignee: Rohm Co., Ltd.Inventors: Kiyotaka Umemoto, Ko Takemura
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Patent number: 7595620Abstract: A control signal generating circuit (1) comprises a comparator (10) for comparing an output voltage VO with a reference voltage outputted from a reference voltage source (11), a flipflop (12) set by the output of the comparator (10), and a pulse control circuit (13) which receives an input voltage VIN, a reference voltage VREF2, and the inverted output of the flipflop (12), sets the on time in accordance with the ratio between the input voltage VIN and the reference voltage VREF2, and resets the flipflop (12) when the on time elapses after the output pulse of the flipflop (12) rises. The output pulse of the flipflop (12) is outputted as a control signal into a driver logic circuit (2). The driver logic circuit (2) performs on/off control of NMOSs (3, 4) according to the control signal. Thus, a switching regulator capable of operating at high speed can be realized.Type: GrantFiled: March 9, 2005Date of Patent: September 29, 2009Assignee: Rohm Co., Ltd.Inventors: Masaru Sakai, Kiyotaka Umemoto, Shogo Hachiya
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Publication number: 20090134860Abstract: In a power supply apparatus that is so configured as to produce from an input voltage an output voltage Vo within a predetermined permissible variation range, the output voltage Vo is so controlled as to decrease within the permissible variation range as the output current lo increases.Type: ApplicationFiled: December 30, 2008Publication date: May 28, 2009Applicant: Rohm Co., Ltd.Inventors: Kiyotaka Umemoto, Ko Takemura
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Publication number: 20090128219Abstract: A semiconductor device (100) includes a MOS transistor (10) having a back gate region “a”, a first region “b” serving as one of a source region and a drain region, and a second region “c” serving as the other of the source region and the drain region. The semiconductor device further includes an input terminal (20) connected to the first region “b” and to which an input voltage is applied from outside the semiconductor device (100), an output terminal (30) connected to the second region “c” and outputting an output voltage outside the semiconductor device (100), and a back gate control circuit (40) for applying the input voltage or the output voltage to the back gate region “a”. With this configuration of the semiconductor device having the output MOS transistor, even when a reverse bias is applied between the input and the output terminal, the terminals are insulated from each other and lowering of the drain current by the substrate bias effect can be suppressed.Type: ApplicationFiled: June 16, 2006Publication date: May 21, 2009Applicant: Rohm Co., Ltd.Inventor: Kiyotaka Umemoto
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Patent number: 7486061Abstract: In a power supply apparatus that is so configured as to produce from an input voltage an output voltage Vo within a predetermined permissible variation range, the output voltage Vo is so controlled as to decrease within the permissible variation range as the output current Io increases. This configuration offers an output voltage with an improved transient characteristic against an abrupt variation in the output current and simultaneously permits reduction of the power consumed when the output current increases.Type: GrantFiled: November 15, 2006Date of Patent: February 3, 2009Assignee: Rohm Co., Ltd.Inventors: Kiyotaka Umemoto, Ko Takemura
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Publication number: 20080019160Abstract: A DC/DC converter includes a switching element which is opened and closed to supply power from an input power supply VCC, through a coil to an output terminal, which is connected to a load, and to adjust the voltage at the output terminal. The DC/DC converter also includes a coil current detection resistor arranged to detect a coil current a smoothing capacitor connected to the load side of the coil current detection resistor and arranged to smooth the voltage at the output terminal, a reference current value control circuit arranged to detect the voltage on the coil side of the coil current detection resistor to control a reference current value of the coil current, a clock generator arranged to generate a reference clock, and a feedback circuit arranged to close the switching element in synchrony with the reference clock and to open the switching element when the coil current exceeds the reference current value.Type: ApplicationFiled: November 11, 2004Publication date: January 24, 2008Applicant: ROHM CO, LTDInventors: Kiyotaka Umemoto, Ko Takemura
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Publication number: 20070182395Abstract: A control signal generating circuit (1) comprises a comparator (10) for comparing an output voltage VO with a reference voltage outputted from a reference voltage source (11), a flipflop (12) set by the output of the comparator (10), and a pulse control circuit (13) which receives an input voltage VIN, a reference voltage VREF2, and the inverted output of the flipflop (12), sets the on time in accordance with the ratio between the input voltage VIN and the reference voltage VREF2, and resets the flipflop (12) when the on time elapses after the output pulse of the flipflop (12) rises. The output pulse of the flipflop (12) is outputted as a control signal into a driver logic circuit (2). The driver logic circuit (2) performs on/off control of NMOSs (3, 4) according to the control signal. Thus, a switching regulator capable of operating at high speed can be realized.Type: ApplicationFiled: March 9, 2005Publication date: August 9, 2007Inventors: Masaru Sakai, Kiyotaka Umemoto, Shogo Hachiya
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Patent number: 7202652Abstract: A motor driving apparatus which includes a pair of field-effect transistors connected in series between a first supply voltage and a second supply voltage lower than the first supply voltage, an output smoothing circuit connected to a node between the two field-effect transistors, a driver for controlling on/off states of the field-effect transistors according to an input signal, and a detector for detecting on/off states of body diodes attached respectively to the field-effect transistors. Only after either of the body diodes is detected being on are the field-effect transistors respectively turned on to produce an output corresponding to the input signal so as to eventually produce a desired output voltage from the first supply voltage.Type: GrantFiled: March 9, 2005Date of Patent: April 10, 2007Assignee: Rohm Co, Ltd.Inventors: Kiyotaka Umemoto, Ko Takemura