Switching device

摘要

A PNPN semiconductor switching device for igniter circuits comprises first and third diffusion layers of N-type conductivity semiconductor material, second and fourth diffusion layers of P-type conductivity type semiconductor material, and a first buried region of N-type conductivity in the third layer adjacent to the junction between the second and third layers. The buried region has a greater impurity concentration than the third layer and serves to control the switching voltage of the device The first to third diffusion layers form an NPN transistor and a resistance is formed as part of the transistor base diffusion between the base and emitter diffusion regions of the transistor for controlling the switching current of the device.