| With the development of electronic information industry, the sine signal ismore an more applied in the variety of electronic systems, which is also widelyused in the reference signal and the carrier signal. Usually the sine signal ismainly produced by the way of analog circuits or direct digital frequencysynthesizer. The technology of DDS has lots of advantages: such as the rapidlysignal conversion rate, the output signal of the high stability and the continuouslyphases of the output waveform, but the excessive price of it limits the applicationin some areas. So this paper designed a method of analog circuits generatesinusoidal signal wave.In this paper, it devises a sinusoidal signal generator, which is based theWien bridge circuit. It introduces the domestic development situation of wavegenerator, based on the basic principle of the Wien bridge circuit, and designs atwo-stage operational amplifier, which can be applied in the sine signal generator.It analyzes the distortion of the waveform, at the same time, analyzes theinfluence factors of sine wave, which include the amplifier open loop gain andbandwidth, phase margin, the output voltage swing, common mode rejection ratioand power supply rejection ratio and so on. At last, the frequency selectivenetwork and steady amplitude circuit are added to the output of amplifier. Andsimulates the whole circuit, The output of sine wave meets the designrequirements.Under the condition of5V power supply voltage, Wien bridge circuit of theamplifier circuit are simulated and analyzed by using the process of0.5μm. Theoperational amplifier circuit based on Wien bridge circuit has the gain of105.3dB, bandwidth of38.86MHz, common mode rejection ratio of87.1dB andpower supply rejection ratio of83.91dB. The sine wave frequency is1.109kHz,center potential is2.5V, amplitude is2.58V, and distortion is less than2%. The output waveform is smooth, the lower degree of distortion and clear, and highstability. The range of operating frequency is100Hz to100KHz. |
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