| 摘要 |
An object of the present invention is to provide a power supply circuit including a charge-pumping booster section which uses switching elements provided only by N-channel transistors yet does not have a problem of voltage drop by threshold value. In a booster section (11a), capacitors (C1) and (C2) have their respective first terminals connected with transistors (Q1, Q3) and (Q2, Q4) respectively. Each transistor has its gate terminal supplied with control signals generated in a driver section (11b). The driver section (11b) includes capacitors (C3, C4) connected with input terminals (Ti3, Ti4) for respective supply of clock signals DCK2, DCK2B each having a voltage alternating between −VDD and VDD (VDD represents an input supply voltage from outside), as level-shifted signals of clock signals DCK1, DCK1B which are supplied to second terminals of the capacitors (C1, C2) respectively. In this arrangement, the driver section 11b generates signals each having a voltage alternating between VDD and 3VDD, as the control signals.
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