| 摘要 |
PURPOSE: A digital single chip stereo amplitude modulator is provided to offer a digital stereo amplitude modulator embodied as a single chip in order to obtain the output of high integration, high stability and high resolution. CONSTITUTION: A phase shift keying angle calculation unit(201) gets a phase shift keying angle for two external voice signals. An analog-digital converter(202) converts the angle into a digital value. An external signal adder(203) adds the two external voice signals. An analog-digital converter(204) converts the composite output value into a digital value. A digital single chip stereo amplitude modulator(206) receives the output value of the phase shift keying angle calculation unit(201), the output value of the external signal adder(203), the output value of a carrier frequency adjusting unit(205), a stereo/mono control signal, a test mode control signal, a carrier wave suppress/large carrier wave amplitude modulation mode control signal, a clock and a reset signal and carries out stereo amplitude modulation for them. A digital-analog converter(207), receiving the output of the digital single chip stereo amplitude modulator(206), converts it into an analog signal. The analog signal is outputted as a stereo amplitude modulation signal through a low pass filter(208).
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