| 摘要 |
PROBLEM TO BE SOLVED: To provide a drive circuit for a capacitive load that can precisely reduce power consumption and guarantee stable operation even in a high frequency range, and a liquid discharge apparatus. SOLUTION: The drive circuit has a drive signal generating unit 31 for generating a drive signal S2 to drive a piezoelectric element 11 via a driving transistor pair 31A, and a source voltage generating unit 32 for generating a high voltage side source voltage VU and a low voltage side source voltage VL and applying the high voltage side source voltage VU and the low voltage side source voltage VL to the respective collectors of transistors TR1, TR2. The source voltage generating unit 32 has a charge pump 32 with a capacitor connected in series or parallel with a voltage source VS via a power transistor pair to generate the high voltage side source voltage VU and the low voltage side source voltage VL. According to a control signal S3 whose waveform follows that of the drive signal S2, the power transistor pair causes the low voltage side source voltage VL to follow the drive signal S2 in a voltage range lower than that of the drive signal S2, thereby causing the high voltage side source voltage VU to be controlled to follow the drive signal S2 in a voltage range higher than that of the drive signal S2. COPYRIGHT: (C)2009,JPO&INPIT
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