Patent ID: 8912840
Filing Date: 2014-12-16
Classification: H03K

Abstract:
1. A switching device for switching a current between a first terminal and a second terminal, comprising: a series arrangement of at least two JFETs of which a lowermost JFET is connected to a first terminal or the lowermost JFET is connected in a cascade arrangement via a control switch to the first terminal, and of one or more further, upper JFETs which is or are connected in series to the lowermost JFET, wherein the JFET which is distanced furthest from the lowermost JFET is indicated as the uppermost JFET and with its drain terminal is connected to a second terminal, wherein a passive circuit network for the dynamic activation of the gate voltages of the JFETs is connected between the gate terminals of the JFETs and the first terminal, wherein the passive circuit network in each case between the gates of two consecutive JFETs comprises diodes which are operated in the blocking direction, wherein an additional circuit is connected in each case between the gate terminals of the upper JFETs and the cathode terminals of the diodes of the circuit network, or between anode terminals of the diodes of the circuit network and the gate terminals of assigned JFETs, and this additional circuit keeps the potential of the respective gate terminal high with respect to the associated source terminal, during the dynamic switching-on as well as in the stationary switched-on state; wherein the additional circuit comprises one or more diodes which are operated in series and in the blocking direction between the gate terminals and the cathode terminals; and, wherein the additional circuit comprises one or more capacitors which are in each case parallel to the diodes operated in the blocking direction.