SOLID-STATE HIGH VOLTAGE SWITCH AND SWITCHING POWER SUPPLY

A switching circuit (50) comprising cascaded transistor stages (52a, 52b. . . 52n and 54), connected between a high voltage terminal (62) and a sense resistor (RS) coupled to a low voltage terminal (64). The transistor stage (54) closest to the sense resistor (RS) is referred to as a current gain stage (54), and all the other transistor stages (52a, 52b. . . 52n) are referred to as component stages (52a, 52b. . . 52n). Blocking diodes (DD) are connected across all stages (52a, 52b. . . 52n and 54), forming a continuous path between the high voltage terminal (62) and the low voltage terminal (64). When an enable signal is provided to the current gain stage (54), the transistor stages (52a, 52b. . . 52n and 54) sequentially enter conduction, beginning with the current gain stage (54) and proceeding through the component stages (52a, 52b. . . 52n). As each transistor stage (52a, 52b. . . 52n) enters conduction, the resulting voltage drop will cause each corresponding blocking diode (DD) to avalanche, allowing current to flow. Eventually, all of the component stages (52a, 52b. . . 52n) are turned on, creating a conductive path through the stages (52a, 52b. . . 52n) and completing the switching of the switching circuit (50).