Patents by Inventor Hidekiyo Ozawa

Hidekiyo Ozawa 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).

  • Patent number: 8368373
    Abstract: To provide a control circuit of power supply unit, power supply unit and control method thereof capable of setting and adjusting a voltage value of output voltage flexibly corresponding to an instruction from outside, a voltage adjusting portion AD for adjusting first voltage setting information inputted from outside to real voltage information is provided and the voltage value of the output voltage of the power supply unit is controlled based on real voltage information outputted from the voltage adjusting portion AD. The first voltage setting information inputted from outside enables a desired output voltage to be set up by adjusting the real voltage information flexibly even if information relating to the setting of voltage set as output voltage to an external device which is a supply destination is different from actually necessary voltage value.
    Type: Grant
    Filed: October 5, 2006
    Date of Patent: February 5, 2013
    Assignee: Fujitsu Semiconductor Limited
    Inventors: Hidekiyo Ozawa, Toru Nakamura
  • Patent number: 7960946
    Abstract: A power supply circuit charging a secondary battery by a DC-DC converter using a switching element and an inductance element includes a current adjustment circuit. The current adjustment circuit adjusts a charging current of the secondary battery by turning on/off the switching element according to a voltage difference of a lower one of a reference voltage and a first control voltage corresponding to a temperature of the secondary battery from a current detection voltage corresponding to the charging current of the secondary battery.
    Type: Grant
    Filed: February 15, 2008
    Date of Patent: June 14, 2011
    Assignee: Fujitsu Semiconductor Limited
    Inventors: Hidekiyo Ozawa, Toru Nakamura
  • Patent number: 7957165
    Abstract: A DC-DC conversion circuit is configured by including a plurality of control signal generation circuits, a plurality of soft-start control circuits, and a start control circuit. The plurality of control signal generation circuits correspond to the plurality of control signals, and generate a corresponding control signal of the plurality of control signals based on a corresponding output value of a plurality of output values. The plurality of soft-start control circuits correspond to the plurality of control signals, and control a variation of the corresponding control signal at a start time of the DC-DC conversion circuit. The start control circuit instructs the corresponding soft-start control circuit to start operation in accordance with a change of the control signal taking part in an output control at the start time of the DC-DC conversion circuit.
    Type: Grant
    Filed: February 15, 2008
    Date of Patent: June 7, 2011
    Assignee: Fujitsu Semiconductor Limited
    Inventors: Morihito Hasegawa, Hidekiyo Ozawa
  • Patent number: 7948219
    Abstract: The control circuit comprises: a detecting portion COMP1 for detecting a status transition of a first signal FR at the connecting point P which changes at a constant cycle corresponding to current flowing through the antiparallel diode D when the main switch device FET is turned OFF; and a phase difference adjusting portion 30, 40 for adjusting the phase difference by adjusting the output timing of the second signal FP corresponding to a phase difference between the phase of the first signal FR detected by the detecting portion COMP1 and the phase of the second signal FP generated based on the first signal of one cycle before and the rectification switch device FET2 is turned ON corresponding to the second signal FP whose output timing is adjusted by the phase difference adjusting portion 30, 40.
    Type: Grant
    Filed: September 25, 2007
    Date of Patent: May 24, 2011
    Assignee: Fujitsu Semiconductor Limited
    Inventors: Morihito Hasegawa, Hidekiyo Ozawa
  • Patent number: 7944190
    Abstract: The control circuit 30 of power supply unit and power supply unit 10 controlling output power with electric power supplied from the external power 15, comprise a monitoring portion 40 monitoring current I1 and voltage outputted from the external power supply 15 and output power of the external power supply 15 and a setting portion e1 which sets an upper limit value of current outputted from the external power supply 15 based on a monitoring result of the monitoring portion 40.
    Type: Grant
    Filed: August 15, 2007
    Date of Patent: May 17, 2011
    Assignee: Fujitsu Semiconductor Limited
    Inventors: Hidekiyo Ozawa, Morihito Hasegawa
  • Patent number: 7928601
    Abstract: A DC-DC converter for controlling the order for providing a semiconductor integrated circuit device with a plurality of power supply voltages. A switch control circuit controls activation and inactivation of a transistor of the switch circuit based on the comparison result of a first voltage and a reference voltage and a notification signal provided to the switch control circuit. The switch control circuit generates a second voltage that is higher than the first voltage when the first voltage is higher than the reference voltage and the notification signal indicates that other semiconductor integrated circuit devices are ready to operate.
    Type: Grant
    Filed: April 8, 2005
    Date of Patent: April 19, 2011
    Assignee: Fujitsu Semiconductor Limited
    Inventors: Hidekiyo Ozawa, Hidenobu Ito, Chikara Tsuchiya
  • Patent number: 7781909
    Abstract: It is intended to provide a control circuit of power supply, a power supply and a control method thereof capable of achieving power saving in an integrated circuit and reducing a delay time of the integrated circuit. The control circuit 50 of a power supply 10 which outputs plural DC voltages VCC, VBGP, VBGN each having a different voltage value includes a voltage changing portion SW1 which detects an output current I1 relating to a first DC voltage VCC which is one of the plural DC voltages and sets at least one DC voltage except the first DC voltage VCC based on the detected output current I1, and the like.
    Type: Grant
    Filed: September 7, 2006
    Date of Patent: August 24, 2010
    Assignee: Fujitsu Semiconductor Limited
    Inventors: Hidekiyo Ozawa, Morihito Hasegawa
  • Patent number: 7719136
    Abstract: A control circuit for a power supply device, a power supply device, and the like are provided in which the power supply device has a plurality of DC/DC converters provided for generating voltage while the mutual relationship of potential between the voltage outputs is maintained. The control circuit 20 in the power supply device 10 which outputs different direct current voltages (VCC, VBGP, and VBGN) includes a voltage setting unit 22 for determining the setting level of a second direct current voltage VBGP which has a potential relationship with the setting level of the first direct current voltage VCC which is one of a plurality of the different direct current voltages.
    Type: Grant
    Filed: June 5, 2006
    Date of Patent: May 18, 2010
    Assignee: Fujitsu Microelectronics Limited
    Inventors: Toru Nakamura, Hidekiyo Ozawa
  • Patent number: 7705483
    Abstract: An object of the present invention is to provide a DC-DC converter control circuit capable of maintaining, even when any one of a plural number of DC-DC converters enters the abnormal state due to the occurrence of a failure, a voltage relationship between the output voltage of the faulty DC-DC converter and the output voltage of another DC-DC converter. An error amplifier ERA1G has an inverting input, a first non-inverting input, and a second non-inverting input. A first divided voltage VV1 provided from a first voltage divider circuit VD1 is fed into the inverting input; a reference voltage e1G from ground is fed into the first non-inverting input; and a second divided voltage VV2 provided from a second voltage divider circuit VD2 is fed into the second non-inverting input. The error amplifier ERA1G amplifies the error between the lower of the two voltage inputs fed into the two non-inverting inputs (i.e.
    Type: Grant
    Filed: September 25, 2006
    Date of Patent: April 27, 2010
    Assignee: Fujitsu Microelectronics Limited
    Inventors: Hidekiyo Ozawa, Morihito Hasegawa
  • Patent number: 7701178
    Abstract: A circuit for controlling charging includes a transistor provided on a charging path between a position of a charging terminal and a position of a battery, an input voltage detecting circuit configured to detect a potential of a point on the charging path coupled to the charging terminal's side of the transistor, and a drive circuit configured to control an ON resistance of the transistor between a conductive state and a nonconductive state in response to the potential detected by the input voltage detecting circuit.
    Type: Grant
    Filed: October 1, 2004
    Date of Patent: April 20, 2010
    Assignee: Fujitsu Microelectronics Limited
    Inventors: Masaya Tsukamoto, Akira Haraguchi, Hidekiyo Ozawa
  • Patent number: 7679214
    Abstract: An electronic device provided with a system main unit including a load powered by operational voltage. A system power supply unit, connected to the system main unit, supplies the load with the operational voltage. The system main unit includes a memory circuit for storing initial value data containing a set value for setting the operational voltage of the load. A main unit communication circuit reads the initial value data from the memory circuit and transmits the initial value data to the system power supply unit. The system power supply unit includes a power supply communication circuit for communicating with the main unit communication circuit to receive the initial value data. A voltage generation circuit generates voltage corresponding to the set value.
    Type: Grant
    Filed: August 30, 2006
    Date of Patent: March 16, 2010
    Assignee: Fujitsu Microelectronics Limited
    Inventors: Toru Nakamura, Hidekiyo Ozawa
  • Patent number: 7675267
    Abstract: This invention aims at providing a control circuit of power supply in which a secondary battery and a device are connected in parallel, to output capable of preventing over-charging of the secondary battery and supplying power from the secondary battery to the device, and a control method of the power supply. A device 5G and a secondary battery 2G are connected to a DC-DC converter 1G in parallel. The device 5G is supplied with both a power from the DC-DC converter 1G and a power from the secondary battery 2G. When the secondary battery 2G is in non-charging state, an offset circuit 15G supplies a positive offset for reducing a difference of voltage between a detection signal Vx1G and reference voltage e1G to a reference voltage e1G corresponding to a charging inhibit signal CAS.
    Type: Grant
    Filed: September 27, 2006
    Date of Patent: March 9, 2010
    Assignee: Fujitsu Microelectronics Limited
    Inventors: Hidekiyo Ozawa, Takashi Matsumoto, Takahiro Yoshino, Toru Nakamura
  • Patent number: 7663345
    Abstract: A DC-DC converter for generating a stable output voltage and being applicable to a transient load fluctuation. The DC-DC converter detects an input current, and compares the input current with a rated current of an external power supply. The DC-DC converter controls a positive charging current that is supplied to a secondary battery in accordance with a consumption current of a load so that the input current does not exceed the rated current. The DC-DC converter further controls a negative charging current that is supplied from the secondary battery to the load when the load requires an input current exceeding the rated current.
    Type: Grant
    Filed: August 30, 2006
    Date of Patent: February 16, 2010
    Assignee: Fujitsu Microelectronics Limited
    Inventors: Hidekiyo Ozawa, Takashi Matsumoto, Takahiro Yoshino
  • Patent number: 7545054
    Abstract: A DC-DC converter control circuit can maintain a relationship of voltages established among the output voltages even when the output voltages of DC-DC converters are independently controlled. A first reference voltage with which a high-potential back-gate voltage is controlled and a second reference voltage with which a supply voltage is controlled are dynamically controlled to be varied independently from one another. A supply voltage is applied to the inverting input terminal of a second differential-input amplifier. The second reference voltage is applied to the first non-inverting input terminal of the second differential-input amplifier, and the first reference voltage is applied to the second non-inverting input terminal thereof. The second differential-input amplifier amplifies the difference between a lower one of the first and second reference voltages applied to the two non-inverting input terminals thereof and the supply voltage applied to the inverting input terminal thereof.
    Type: Grant
    Filed: June 6, 2006
    Date of Patent: June 9, 2009
    Assignee: Fujitsu Microelectronics Limited
    Inventors: Hidekiyo Ozawa, Morihito Hasegawa, Toru Nakamura
  • Patent number: 7489528
    Abstract: A power supply control method is adapted to a current-to-voltage conversion circuit which has a transformer for converting and outputting an input power. The power supply control method stops a power supply to the transformer when an output side of the current-to-voltage conversion circuit is in a no-load state, and starts a power supply to the transformer when an external voltage is applied to the output side of the current-to-voltage conversion circuit.
    Type: Grant
    Filed: November 19, 2003
    Date of Patent: February 10, 2009
    Assignee: Fujitsu Limited
    Inventors: Shigeo Tanaka, Hidekiyo Ozawa
  • Patent number: 7423415
    Abstract: A differential output DC-DC converter capable of decreasing power consumption is presented. The differential output DC-DC converter 1 comprises output terminals VP and VM connected to both ends of load, and a switching regulator 10 for passing a source current. It further comprises a third transistor FET3, a choke coil L2, and a fourth transistor FET4 for rectifying a sink current in a flowing direction, and further a second regulator for allowing the sink current to flow, and issuing a voltage higher than a grounding point GND voltage and lower than a voltage of an output terminal VP, to an output terminal VM.
    Type: Grant
    Filed: February 10, 2006
    Date of Patent: September 9, 2008
    Assignee: Fujitsu Limited
    Inventors: Morihito Hasegawa, Hidekiyo Ozawa
  • Publication number: 20080197821
    Abstract: A DC-DC conversion circuit is configured by including a plurality of control signal generation circuits, a plurality of soft-start control circuits, and a start control circuit. The plurality of control signal generation circuits correspond to the plurality of control signals, and generate a corresponding control signal of the plurality of control signals based on a corresponding output value of a plurality of output values. The plurality of soft-start control circuits correspond to the plurality of control signals, and control a variation of the corresponding control signal at a start time of the DC-DC conversion circuit. The start control circuit instructs the corresponding soft-start control circuit to start operation in accordance with a change of the control signal taking part in an output control at the start time of the DC-DC conversion circuit.
    Type: Application
    Filed: February 15, 2008
    Publication date: August 21, 2008
    Applicant: FUJITSU LIMITED
    Inventors: Morihito Hasegawa, Hidekiyo Ozawa
  • Publication number: 20080197814
    Abstract: A power supply circuit charging a secondary battery by a DC-DC converter using a switching element and an inductance element includes a current adjustment circuit. The current adjustment circuit adjusts a charging current of the secondary battery by turning on/off the switching element according to a voltage difference of a lower one of a reference voltage and a first control voltage corresponding to a temperature of the secondary battery from a current detection voltage corresponding to the charging current of the secondary battery.
    Type: Application
    Filed: February 15, 2008
    Publication date: August 21, 2008
    Applicant: FUJITSU LIMITED
    Inventors: Hidekiyo Ozawa, Toru Nakamura
  • Patent number: RE42114
    Abstract: A control system for charging enabling efficient charging of rechargeable batteries in an electronic apparatus which charges its rechargeable batteries by using a charger circuit when driving the apparatus by using an external power source, including first detecting unit for detecting a differential value between a maximum permissible charging current allowed by the rechargeable batteries and a charging current flowing to the rechargeable batteries; second detecting unit for detecting a maximum usable current by detecting a differential value between a maximum supplyable current allowed by the external power source and the current consumption of the apparatus; third detecting unit for detecting a differential value between a maximum useable current and the charging current flowing to the rechargeable batteries; and control unit for controlling the system in accordance with the differential values detected by the first and third detecting units so that the charger circuit generates the maximum charging current
    Type: Grant
    Filed: April 12, 2000
    Date of Patent: February 8, 2011
    Assignee: Fujitsu Semiconductor Limited
    Inventors: Kouichi Matsuda, Mitsuo Saeki, Nobuo Tanaka, Hidekiyo Ozawa
  • Patent number: RE43911
    Abstract: A control system for charging enabling efficient charging of rechargeable batteries in an electronic apparatus which charges its rechargeable batteries by using a charger circuit when driving the apparatus by using an external power source, including first detecting unit for detecting a differential value between a maximum permissible charging current allowed by the rechargeable batteries and a charging current flowing to the rechargeable batteries; second detecting unit for detecting a maximum usable current by detecting a differential value between a maximum supplyable current allowed by the external power source and the current consumption of the apparatus; third detecting unit for detecting a differential value between a maximum useable current and the charging current flowing to the rechargeable batteries; and control unit for controlling the system in accordance with the differential values detected by the first and third detecting units so that the charger circuit generates the maximum charging current
    Type: Grant
    Filed: March 7, 2003
    Date of Patent: January 8, 2013
    Assignee: Fujitsu Semiconductor Limited
    Inventors: Kouichi Matsuda, Mitsuo Saeki, Nobuo Tanaka, Hidekiyo Ozawa