| 摘要 |
A delta modulator includes an integrator, a comparator for sensing the output of the integrator and a flip flop for synchronizing the comparator output to a clock signal and providing an error signal to the input of the integrator. The output of the delta modulator is a data stream having a time-averaged duty cycle that represents the input signal amplitude. The integrator includes an amplifier that is provided with positive feedback. Error caused by the finite open loop gain of the amplifier is cancelled by the positive feedback. As a result, high accuracy is achieved. The integrator amplifier is stabilized by the overall negative feedback of the delta modulator loop.
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