Power supply device
AssigneeOki Electric Industry Co., Ltd.
InventorSatoru Kurotsu
Life of this patent
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Abstract
A reference voltage for obtaining a desired output voltage value, and an output voltage are inputted to an operational amplifier. A PMOS transistor whose on/off operation is controlled by the operational amplifier, outputs an internal node voltage therefrom. A switch control circuit outputs a signal constant in duty ratio, for activating CHG switches and DCHG switches respectively. A voltage dividing capacitor and an output capacitor respectively repeat charging and discharging based on a switching pulse constant in duty ratio. Accordingly, a stable output voltage obtained by series/parallel connection switching operations of two capacitors results in ½ of the internal node voltage.
Claims14
A power supply device having a plurality of capacitors, wherein connected states of the plurality of capacitors are changed during a charging and a discharging cycles to thereby perform DC-DC power conversion, comprising:
- a resistor step-down type power supply circuit;
- and
- a switched capacitor type power supply circuit;
- wherein an output produced from said resistor step-down type power supply circuit is inputted to said switched capacitor type power supply circuit, said resistor step-down type power supply circuit outputs a voltage switchable by the respective capacitors lying within said switched capacitor type power supply circuit during both the charging and discharging cycles in an equilibrium state in which the same potential is applied to the capacitors, and said switched capacitor type power supply circuit performs series/parallel switching operations of the capacitors according to a switching pulse constant in duty ratio.
A power supply device comprising:
- a switched capacitor type power supply circuit for charging a plurality of built-in capacitors by using an internal node voltage during a charging cycle and discharging the plurality of charged capacitors during a discharging cycle to thereby generate an output voltage corresponding to the internal node voltage;
- and
- an internal node voltage adjusting circuit for comparing the output voltage and a reference voltage adjusted to a predetermined level and adjusting the internal node voltage according to the result of comparison.
A power supply device comprising:
- a power supply circuit for supplying a voltage to a first node according to the result of comparison between an output voltage and a reference voltage;
- and
- a plurality of switches for electrically connecting the first node and an electrostatic capacitive element to store an electric charge in the electrostatic capacitive element and electrically disconnecting the first node and the electrostatic capacitive element to discharge the electric charge stored in the electrostatic capacitive element.
Dependencies are inferred from the claim text.