Pulse Signal Generator Conditioning Channel Module Design

Pulse signal generators are an important type of test circuit excitation source,which can generate pulse signals with adjustable amplitude,period,and equality parameters.From the perspective of the pulse signal generator structure,the signal analog conditioning channel of the pulse signal generator is mainly determined by the signal amplitude and the electrometric parameters.This paper mainly studies the signal analog conditioning technology of pulse signal generator,under a large number of theoretical analysis and circuit simulation,a signal analog conditioning scheme is formulated,the corresponding circuit is designed,and the circuit design of the signal analog channel module with the highest frequency of 330MHz pulse signal conditioning is completed,and the research content mainly includes the following points:（1）Pulse waveform characterization and channel scheme designBased on the study of the analog conditioning channel of the bandwidth signal,the time domain characteristics and frequency domain characteristics of the pulse signal with a frequency of up to 330MHz are analyzed,and the bandwidth of the signal analog conditioning channel and the cutoff frequency of the low-pass filter are determined.Theoretical analysis is based on bandwidth,the bandwidth design of signal analog conditioning is completed,and the theoretical basis is provided for the following signal analog conditioning techniques.（2）Amplitude conditioning studies and pulse conditioning circuit designAmplitude conditioning for pulse signals with a repeating frequency of1μHz～330MHz bandwidth,to meet different amplitude specifications at different frequencies,there are limits on the slew rate parameters of the operational amplifier,the division of the amplitude index mode is adopted,and a variety of amplifiers are used to coordinate and condition the pulse signals of different frequency bands in the high-bandwidth amplifier mode and the high-voltage amplifier mode.In addition,the multi-stage amplification and conditioning technology is used to effectively solve the problems of the op amp is limited by the gain and bandwidth product,and the 330MHz pulse signal output 5V_PP and the 50MHz pulse signal output amplitude index with a maximum amplitude of 20Vpp are realized.（3）Voltage window expansion and bias circuit designIn view of this topic,the frequency repeating frequency of 1μHz～330MHz bandwidth pulse signal is biased to achieve the voltage window index of up to±20V,and the±20V voltage window expansion adjustment of the wide-bandwidth pulse signal brings great problems to the signal analog conditioning channel,combined with the low frequency plus bias conditioning technology based on the op amp and bias high frequency conditioning technology can complete the bias circuit design,in addition,the variable voltage source is designed to provide voltage current to the op amp.A bias voltage source is also designed to provide DC bias for the biasing circuit.（4）Drive enhanced circuit designThe impedance switching function can reflect the advanced nature of the pulse signal generator,the output impedance of this topic can be switched 5Ω/50Ω,and the source5Ωto the load 12Ωcan output up to 7V,which requires the current drive capability,so the load sharing configuration mode technology is used to condition the signal and increase the current drive capability.