Compared with other methods to realize linear isolation of analogsignals, the isolation circuit which is composed of high-voltage isolation linearoptocouper module takes the advantage of simpleness, low cost, good performance ofisolation, high linearity and broad band to transfer signals.
By all-round analyzing, we find that the device have many merits such as: simple structure, fine temperature character, high speed, high-voltage isolation and high-capacitance and so on, it will also be used extensively.
Main factors affecting the breakdown properties of insutalors are analysed, on the basis of which a high voltage isolating photocoupler is designed and fabricated. The experiment results show that the device exhibits excellent isolation and high realiability with the peak isolating voltage up to 10 000 V.
Simulation demonstrates that the maximum breakdown voltages of N-and P-channel LDMOS are higher than 320 V,and the isolation structure can withstand the voltage over 300 V,which ensure reliable operation of high-voltage amplification.
SCM controls CPLD by the input/output port through the procedure so as to produce the profile signal for power module. Then the high pressure shielding system controls the power module so as to drive the output transformer for the high frequency high-pressure output of high frequency electricity knife.