Fujitsu Corporation

Fujitsu Semiconductor Limited

Fujitsu Microelectronics Limited

Fijitsu Limited

Hidekiyo Ozawa

Mitsuo Saeki

Hidetoshi Yano

Kouichi Matsuda

Morihito Hasegawa

Kyuichi Takimoto

Seiya Kitagawa

Mituo Saeki

Shigeo Tanaka

Takashi Matsumoto

Toshiyuki Matsuyama

Masafumi Okumura

Toru Nakamura

Nobuo Tanaka

Yoshiaki Sano

Chikara Tsuchiya

Shigeaki Nakazawa

Yoshiro Takeda

Hidenobu Ito

Atsushi Hayakawa

Kazuyoshi Arimura

Takahiro Yoshino

Takeshi Kubo

Toshiaki Tsukuni

Tsutomu Suzui

Akira Yoshida

Yasushige Ogawa

Tetsuo Yamamoto

Kazuhiko Itakura

Akira Haraguchi

Toshihiko Kasai

Toshiro Obitsu

Mikio Itoh

Masahiro Natsume

Kazuhito Fukuoka

Masami Itoyama

Shoji Tajiri

Hirofumi Dogome

Nakazawa Shigeaki

Hisafumi Mitsui

Kuniaki Saito

Masaya Tsukamoto

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.

Control circuit of power supply unit, power supply unit and control method thereof

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 within the range where the charging current flowing to the rechargeable batteries does not exceed either of the maximum permissible charging current and the maximum useable current.

Control system for charging batteries and electronic apparatus using same

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.

Power supply circuit, power supply control circuit, and power supply control method

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.

DC-DC converter with a plurality of soft-start control circuits

The control circuit comprises: a detecting portion COMPfor 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 portionfor 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 COMPand the phase of the second signal FP generated based on the first signal of one cycle before and the rectification switch device FETis turned ON corresponding to the second signal FP whose output timing is adjusted by the phase difference adjusting portion

Control circuit of synchronous rectification type power supply unit, synchronous rectification type power supply unit and control method thereof

The control circuitof power supply unit and power supply unitcontrolling output power with electric power supplied from the external power, comprise a monitoring portionmonitoring current Iand voltage outputted from the external power supplyand output power of the external power supplyand a setting portion ewhich sets an upper limit value of current outputted from the external power supplybased on a monitoring result of the monitoring portion

Control circuit of power supply unit which controls output power of external power supply based upon current from the external power supply, power supply unit and control method thereof

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.

Power supply circuit for providing semiconductor integrated circuit device with a plurality of power supply voltages

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 within the range where the charging current flowing to the rechargeable batteries does not exceed either of the permissible charging current and the maximum useable current.

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 circuitof a power supplywhich outputs plural DC voltages VCC, VBGP, VBGN each having a different voltage value includes a voltage changing portion SWwhich detects an output current Irelating 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 I, and the like.

Control circuit of power supply, power supply and control method thereof

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 circuitin the power supply devicewhich outputs different direct current voltages (VCC, VBGP, and VBGN) includes a voltage setting unitfor 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.

Power source control circuit, power supply device, and control method for the same

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 ERAG has an inverting input, a first non-inverting input, and a second non-inverting input. A first divided voltage VVprovided from a first voltage divider circuit VDis fed into the inverting input; a reference voltage eG from ground is fed into the first non-inverting input; and a second divided voltage VVprovided from a second voltage divider circuit VDis fed into the second non-inverting input. The error amplifier ERAG amplifies the error between the lower of the two voltage inputs fed into the two non-inverting inputs (i.e. the lower of the reference voltage eG and the second divided voltage VV), and the first divided voltage VVfed into the inverting input. The output terminal of the error amplifier ERAG is connected to the input terminal of a PWM unit PG.

DC-DC converter control circuit, DC-DC converter, power supply unit, and DC-DC converter control method

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.

Charge control that keeps constant input voltage supplied to battery pack

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.

Electronic device incorporating system power supply unit and method for supplying power supply voltage

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 deviceG and a secondary batteryG are connected to a DC-DC converterG in parallel. The deviceG is supplied with both a power from the DC-DC converterG and a power from the secondary batteryG. When the secondary batteryG is in non-charging state, an offset circuitG supplies a positive offset for reducing a difference of voltage between a detection signal VxG and reference voltage eG to a reference voltage eG corresponding to a charging inhibit signal CAS. An error amplifier ERAG reduces an actually flowing charging current CCG by an amount corresponding to the offset value as a result of recognizing that the charging current CCG flows more by the amount corresponding to the offset value.

Control circuit of power supply and control method of the power supply

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.

Circuit and method for controlling DC-DC converter

Growing community of inventors

Kasugai, Japan

Hidekiyo Ozawa