| 摘要 |
An amplifier capable of driving an analog load is provided. The amplifier comprises a sigma delta modulator (SDM), a pulse processing circuit, an output stage, and a feedback loop. The SDM produces a plurality of noise-shaped output pulses based upon a digital input signal to the amplifier and an error signal. The pulse processing circuit processes at least a portion of the plurality of noise-shaped output pulses to ensure that each of the noise-shaped output pulses in the portion contains an amount of energy that is as close as possible to the amount of energy in the other pulses. The output stage is coupled to the pulse processing circuit and has first state wherein the output stage provides analog noise-shaped output energy pulses to a load and a second state where the output energy delivered is essentially zero. The feedback loop is coupled between the output stage and the SDM. The feedback loop samples the energy provided to the load during the first state by measuring the load during the second state and generates an error signal based on the difference between the sampled portion of the noise-shaped output pulses and the input digital signal to the amplifier.
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