| 摘要 |
PROBLEM TO BE SOLVED: To reduce power consumption by stopping operation of a charge pump circuit when output voltage of the charge pump circuit is detected and required voltage is obtained. SOLUTION: Voltage being lower than the reference voltage by threshold voltage is outputted by a first electric field effect transistor. Voltage being lower than output voltage of a charge pump by threshold voltage is outputted by a second electric field effect transistor. Output of the first and the second electric field effect transistors are inputted respectively to a gate and a source of a third electric field effect transistor. When difference between both input exceeds the threshold voltage, the third electric field effect transistor is conducted, a current is made to flow. Operation of the charge pump is controlled by this current. If threshold voltage of the first and the third electric field effect transistors are the same value, difference between output voltage of the charge pump and the reference voltage is made a threshold voltage of the second electric field effect transistor. COPYRIGHT: (C)2003,JPO
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