Patent ID: 7728651

Claim:
A voltage conversion device for boosting an input voltage to output a boosted output voltage, the device comprising: a booster circuit; and a control circuit for controlling operation of the booster circuit, wherein the booster circuit comprises: a booster capacitor; an output capacitor connected between an output node for outputting the output voltage and a reference node for receiving a reference voltage; and a connection switch section for connecting one terminal of the booster capacitor to an input node for receiving the input voltage and the other terminal of the booster capacitor to the reference node in a charging mode, and connecting the other terminal of the booster capacitor to the input node and the one terminal of the booster capacitor to the output node in a boosting mode, the connection switch section includes a first drive transistor for switching the connection between the input node and the one terminal of the booster capacitor in response to a first control signal swinging between the output voltage and the reference voltage, the control circuit comprises: a first control transistor connected between a first input node for receiving a first input signal swinging between the output voltage and a first bias voltage and an intermediate node for outputting the first control signal, the first control transistor receiving the first bias voltage at its gate; and a second control transistor connected between a second input node for receiving a second input signal swinging between a second bias voltage and the reference voltage in synchronization with the first input signal and the intermediate node, the second control transistor receiving the second bias voltage at its gate, the voltage difference between the output voltage and the second bias voltage is smaller than or equal to a source-drain breakdown voltage of the second control transistor, and the voltage difference between the first bias voltage and the reference voltage is smaller than or equal to a source-drain breakdown voltage of the first control transistor.