摘要 |
A voltage transforming circuit comprises a constant-voltage regulator circuit for receiving a first voltage from a first voltage source and outputting a second voltage having the same polarity as the first voltage and a predetermined absolute value lower than the same, a step-up circuit, having a plurality of output terminals, for receiving the second voltage and a first synchronization signal, the step-up circuit stepping up the absolute value of the second voltage and controlling the operation of charging capacitors, thereby outputting from the output terminals a plurality of stepped-up voltages of the same polarity having absolute values higher than the second voltage, a level shifter circuit for receiving a second synchronization signal which uses the first voltage as one of logic levels, and receiving that one of the stepped-up voltages which has a highest absolute value higher than that of the first voltage, the level shifter circuit shifting the voltage of the one of logic levels to the highest absolute value of the stepped-up voltages, thereby creating the first synchronization signal, and a one-way conductive element connected between the first voltage source and that one of the output terminals of the step-up circuit from which the stepped-up voltage of the highest absolute value is output.
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