Matrix Network Spectrum Analysis System Based On AD5933

PIG is a three-pin ceramic chip for acceleration sensor. It’s impedance exhibits a regular continuous change with the input frequency. Frequency of input occurs when the impedance of the chip presents minimum is the minimum frequency and it is very important. This article design the matrix spectral analysis system based on AD5933,which is applied to the PIG’s laser adjustment processing.PIG has three probe test points A, B and C, it is required to find the input frequency is than the minimum impedance value between the AC, BC, ABC and AB, through the microcontroller as well as the use of some chip to realize the switch between the A, B, C, and therefore referred to as the matrix formula. Because of the quick speed of the laser trimming, the detection of a single spectrum analyzer’s speed is2seconds, so the formation of a network structure with10spectrum analyzer to match the laser trimming is spectrum analysis system network.AD5933is a high precision impedance converter, integrated on-chip frequency generator is12,1MSPS ADC.AD5933allows users to customize the start frequency, frequency resolution and scan points frequency scanning.External complex impedance, excited by the sine wave signal which generated from the frequency generator and the response signal of the complex impedance change into a voltage signal to be sampled by the ADC chip, and then subjected to Fourier transform by the DSP, after conversion of the scanning spot can be obtained returned data of the real part and the imaginary part of the data, calculated by the formula to obtain the impedance magnitude and phase.Select the channel, then apply the AD5933output frequency from28K to33K, sampling the sampling resistor, can quickly get the maximum impedance frequency through the microcontroller. Sampling speed, getting two channel’s frequency simply is 44ms and20Hz sampling accuracy, simple user operation after the preparation of internal procedures, circuit design is rigorous and simple, its performance is stable and reliable through the data.