DC-DC converter and storage apparatus

A DC-DC converter comprising:

• switching means for coupling N first capacitors having identical capacitances in series, and coupling M second capacitors in parallel to each other and in parallel to the N first capacitors in a first connection state, and supplying thereto an external power supply voltage to be charged thereby, and for coupling the N first capacitors in parallel to each other and the M second capacitors in series to each other and in series to the N first capacitors in a second connection state;
• and
• varying means for varying a duty ratio of a charging timing of the N first capacitors and the M second capacitors in the first connection state, so as to output an internal power supply voltage which is variable,
• wherein said varying means includes a comparator which generates an output pulse by comparing the internal power supply voltage and a reference voltage, and a switch having an ON/OFF state controlled by the output pulse and supplying the external power supply voltage to the N capacitors or to one of the N capacitors.

A storage apparatus comprising:

• an internal circuit;
• a storage section;
• and
• a DC-DC converter which supplies an internal power supply voltage to said internal circuit,
• said DC-DC converter comprising:
• switching means for coupling N capacitors having identical capacitances in series in a first connection state and supplying thereto an external power supply voltage to be charged thereby, and for coupling the N capacitors in parallel in a second connection state;
• and
• varying means for varying a duty ratio of a charging timing of the N capacitors in the first connection state, so as to output an internal power supply voltage which is variable,
• wherein said varying means of said DC-DC converter includes a comparator which generates an output pulse by comparing the internal power supply voltage and a reference voltage, and a switch having an ON/OFF state controlled by the output pulse and supplying the external power supply voltage to the N capacitors or to one of the N capacitors.

A storage apparatus comprising:

• an internal circuit;
• a storage section;
• and
• a DC-DC converter which supplies an internal power supply voltage to said internal circuit,
• said DC-DC converter comprising:
• switching means for coupling N first capacitors having identical capacitances in series, and coupling M second capacitors in parallel to each other and in parallel to the N first capacitors in a first connection state, and supplying thereto an external power supply voltage to be charged thereby, and for coupling the N first capacitors in parallel to each other and the M second capacitors in series to each other and in series to the N first capacitors in a second connection state;
• and
• varying means for varying a duty ratio of a charging timing of the N first capacitors and the M second capacitors in the first connection state, so as to output an internal power supply voltage which is variable,
• wherein said varying means of said DC-DC converter includes a comparator which generates an output pulse by comparing the internal power supply voltage and a reference voltage, and a switch having an ON/OFF state controlled by the output pulse and supplying the external power supply voltage to the N capacitors or to one of the N capacitors.