| 摘要 |
PROBLEM TO BE SOLVED: To obtain a circuit assembly that doubles battery voltage. SOLUTION: The circuit assembly includes a charge pump 12, supplied with power by the battery voltage and controlled by a clock generator 10, and the supply voltage for the clock generator is set as the output voltage of the charge pump 12. The source/drain circuit of a field-effect transistor P4 is inserted into the connection between the output of the charge pump 12 and a battery 26, and the field-effect transistor P4 is on, when the gate voltage thereof is lower than the source voltage thereof. The gate of the field-effect transistor P4 is connected with the output circuit branch N2 of current mirror circuit 32, and limited small current is led out of the gate to the ground. An auxiliary charge pump 22, that receives supply voltage from the output of the charge pump 12 and is similarly controlled by the clock generator 10, is installed. The voltage, produced by the auxiliary charge pump 22, is applied to the gate of the field-effect transistor P4 to switch it off.
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