| 摘要 |
PROBLEM TO BE SOLVED: To provide a Class D amplifier which provides volume control function by varying a bus voltage with respect to output step. SOLUTION: In a Class D audio amplifier, comprising a gain stabilization feedback loop in which volume control is achieved by varying the bus voltage, changes in the bus voltage are compensated for by complementary changes in the gain of a compensation element in feedback loop so the signal level at the output of the Class D stage can be adjusted, independently of the feedback. A digital attenuator can be employed ahead of the amplifier to shift the effective gain of the amplifier output, to provide additional volume control range. COPYRIGHT: (C)2005,JPO&NCIPI
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