Simple MOSFET-Based High-Voltage Nanosecond Pulse Circuit

Abstract

Using simple but powerful electronics concepts, such as a mass produced Schmitt trigger and integrated MOSFET driver in novel circuit applications, a simple 400-V 75-ns pulse generator (pulser) has been designed, developed, and tested. For a 50-/spl Omega/ matched load, the pulser produces extremely well-defined, repetitive high-voltage pulses that are free from overshoot and ringing. The width of the pulses is adjustable from 75 ns to 10 ms with the fall times of a few tens of nanoseconds for a negative wave and a repetition period of 1.5 /spl mu/s with the existing setup. By upgrading to a more complex driver circuit, much lower pulsewidths are possible. Using a 1-4 mm standard commercial cuvette, it is possible to generate electric fields of 4-1 kV/cm with this pulser. The purpose is to try to do electroporation mediated gene therapy on mammalian cells at higher electrical field strengths and submicrosecond or microsecond pulsewidths compared to conventional 200 V/cm and tens of millisecond-duration pulsewidths.