| 摘要 |
A method to linearize the characteristic of a Class-D amplifier is achieved, by compensating for the pulse-area-error, caused by a non-constant power-supply and similar circuit inconsistencies. A Class-D Amplifier typically converts the PDM (Pulse Density Modulated) input signal with a Sigma Delta Modulator and typically uses an H-Bridge as the Class-D power output stage. A fundamental idea is to keep the time-voltage area of every pulse constant. To achieve this, the circuit integrates the power supply voltage, starting with the PDM input pulse and stopping, when the defined time-voltage reference is reached. To compensate not only for power supply variations, but also for e.g. the voltage drop across the output devices, the integrator's input would be more directly referenced to the actual voltage across the output load.
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