Fujitsu Microelectronics Limited

Fujitsu Semiconductor Limited

Toru Nakamura

Hidekiyo Ozawa

Takashi Matsumoto

Morihito Hasegawa

Takahiro Yoshino

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 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 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 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 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.

Growing community of inventors

Kasugai, Japan

Toru Nakamura