SCR Switching with Ionizing Radiation

A model is developed that predicts the critical dose of ionizing radiation required to trigger an SCR as a function of device parameters and biasing. This model also explains the long delay time observed between the ionizing pulse and device switching. The model makes use of the charge control concept. In general, computer solutions are required. A linear approximation is also developed that gives a good estimate in many cases. A method to obtain all parameters needed in the model is presented.