Power supply system and method for controlling output voltage
AssigneeFujitsu Microelectronics Limited
InventorsMasatoshi Kokubun, Takashi Matsumoto
Life of this patent
Estimating the term…
Abstract
A power supply system including an external power supply unit generating direct-current output voltage and an electronic device connected to the external power supply unit and operable on the output voltage of the external power supply unit. The external power supply unit includes a voltage control circuit receiving control current and controlling the output voltage of the external power supply unit in accordance with the control current. The voltage control circuit controls the output voltage of the external power supply unit to be equal to the minimum voltage possible for the external power supply unit to generate when the control current is minimum.
Claims16
A power supply system comprising:
- an external power supply unit generating direct-current output voltage;
- and
- an electronic device coupled to the external power supply unit and operable on the output voltage of the external power supply unit;
- the external power supply unit including a voltage control circuit receiving control current and controlling the output voltage of the external power supply unit in accordance with the control current;
- the electronic device including:
- a rechargeable battery generating battery voltage;
- a system circuit that operates on system voltage generated from at least either one of the output voltage of the external power supply unit and the battery voltage of the rechargeable battery;
- and
- a detection circuit detecting the difference between a detection subject, which includes at least one of the battery voltage of the rechargeable battery, an output current of the external power supply unit, and a charging current charging the rechargeable battery, and a reference signal, which is in accordance with the detection subject, and generating the control current in accordance with the detected difference;
- and
- wherein the voltage control circuit controls the output voltage of the external power supply unit to be equal to the minimum voltage possible for the external power supply unit to generate when the control current is minimum.
A method for controlling direct-current output voltage generated by an external power supply unit in accordance with control current generated by an electronic device, the method comprising:
- generating the control current in accordance with the difference between a detection subject, which includes at least one of battery voltage of a rechargeable battery included in the electronic device, an output current of the external power supply unit, and a charging current charging the rechargeable battery, and a reference signal, which is in accordance with the detection subject, with the electronic device;
- supplying the control current from the electronic device to the external power supply unit;
- and
- controlling the output voltage of the external power supply unit in accordance with the control current, said controlling including controlling the output voltage to be equal to the minimum voltage possible for the external power supply unit to generate when the control current is minimum.
A power supply system comprising:
- an external power supply unit converting an alternating-current voltage to a direct-current voltage and outputting the direct-current output voltage from an output terminal;
- and
- an electronic device including a first terminal receiving the output voltage from the output terminal of the external power supply unit and operable on the output voltage of the external power supply unit, the electronic device generating a control current;
- the external power supply unit including a control terminal receiving the control current and a voltage control circuit controlling the output voltage of the external power supply unit as a function of the control current;
- the electronic device including:
- a rechargeable battery generating battery voltage;
- a system circuit that operates on system voltage generated from at least either one of the output voltage of the external power supply unit and the battery voltage of the rechargeable battery;
- and
- a detection circuit detecting the difference between a detection subject, which includes at least one of the battery voltage of the rechargeable battery, an output current of the external power supply unit, and a charging current charging the rechargeable battery, and a reference signal, which is in accordance with the detection subject, and generating the control current in accordance with the detected difference;
- and
- wherein the voltage control circuit controls the output voltage of the external power supply unit to be equal to the minimum voltage possible the external power supply unit to generate when the control current is minimum.
Dependencies are inferred from the claim text.