A Generator of Rectangular Pulses Based on a Serial Connection of Mosfet with Umax = 4500 V

The purpose of the article is to show the advantages of a new design of a high-voltage rectangular pulse generator. Known analogues combine modules: signal generator; high-voltage key of N identical transistors (Qk, k = 1….N) connected in series; gate driver of leading Qk; high-voltage power source, its electromotive force, emf (E), feeds all Qk and load (R) of the key. In analogs, divider resistors (rk) and snubbers balance equality of voltages Uk on all Qk. Under nonideal balance conditions E ≈ 0.7NUmax, where Umax is the maximum operating voltage of Qk. The new solution differs in that the high-voltage power source sets not one but N emf Ek (Ei/Ej = const (i, j); i ≠ j; i, j = 1, 2, …, N) and each Ek feeds its Qk through the load Rk. Experiments and simulations have revealed advantages of the new design: (1) the simplicity of the circuit and key tuning, (2) the fast transition ON→OFF for all Qk (as Rk is small, Rk $$ \ll $$ rk), (3) the high pulse repetition rate, and (4) the greatly improved balancing of Uk voltages allows the Ek emf to be set so that ΣUk ≈ ΣUk, max at Ui, max ≠ Uk, max. The generator with the key based on two different MOSFETs (IXTL2N450 and IXTT1N450HV, Umax = 4500 V) and with a source where the E2 = 2E1 were used to excite vacuum ion emission from liquid Ga-based alloys.