Boosting method and apparatus
AssigneeFujitsu Limited
InventorTakahiko Sato
Life of this patent
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Abstract
If single-stage boosting is selected by a mode selection circuit, drive signals (S1, S3) are supplied as in-phase signals, and a switch (SW1) is kept closed by a control signal (S2), thereby controlling first and second charge pumps to boost the power supply voltage at the same timing. If two-stage boosting is selected, drive signals (S1, S3) are supplied as complementary signals, and the switch (SW1) is controlled by a control signal (S2), thereby controlling the first charge pump to boost the power supply voltage and controlling the second charge pump to further boost the boosted voltage. By this operation, even if single-stage boosting is selected, the first and second charge pumps can be used as a single charge pump.
Claims12
A boosting apparatus for boosting a power supply voltage and outputting a boost voltage, said apparatus comprising:
- cascade-connected first and second boosting circuits;
- a selection circuit for outputting a boosting mode signal;
- and
- a control circuit for controlling said first and second boosting circuits in accordance with said boosting mode signal,
- wherein said control circuit controls said first and second boosting circuits at the same phase to boost power supply voltages by a one-stage boosting when said boosting mode signal indicates a first mode, and controls said first and second boosting circuits at different phases to boost power supply voltages by a two-stage boosting when said boosting mode signal indicates a second mode.
A boosting apparatus for boosting a power supply voltage and outputting a boost voltage, said apparatus comprising:
- cascade-connected boosting circuits
- a selection circuit for outputting a boosting mode signal;
- and
- a control circuit for controlling said boosting circuits in accordance with said boosting mode signal,
- wherein each of said cascade-connected boosting circuits comprises a boosting capacitor to be charged with a voltage applied from a power supply or the boosting circuit of a preceding stage, and a switch connected with said boosting capacitor to supply an output of said boosting circuit,
- wherein said control circuit controls all of said boosting circuits at the same phase to boost power supply voltages by a one stage boosting when said boosting mode signal indicates a first mode, and controls said boosting circuits at different phases in series to boost power supply voltages by multi-stage boosting when said boosting mode signal indicates a second mode.
A boosting apparatus for boosting a power supply voltage and outputting the voltage, comprising:
- first and second boosting sections each including cascade-connected boosting circuits;
- a selection circuit for outputting a boosting mode signal;
- and
- a control circuit for controlling said first and second boosting sections and said boosting circuits therein in accordance with said boosting mode signal,
- wherein said control circuit performs control to said first and second boosting sections at different phases to alternately output voltages respectively boosted by said first and second boost selections from said first and second boosting sections, and controls all boosting circuits in said boosting sections to boost voltages at the same phase when said boosting mode signal indicates a first mode.
A boosting method using a boosting apparatus including cascade-connected first and second boosting circuits, said method comprising the step of a first and second boosting circuits are controlled to boost power supply voltages at the same phase when twofold boosting is designated by said boosting mode signal, and controlled to boost power supply voltages at different phases when threefolds boosting is designated by said boosting mode signal.
Dependencies are inferred from the claim text.