MONOLITHIC OVERVOLTAGE PROTECTION DEVICE

摘要

A protection device against overvoltages liable to occur between two supply terminals (A, B) comprises between the supply terminals, an avalanche triggered thyristor (6) having a determined break-over voltage (VBO) This system further comprises a zener diode (4) in parallel and reversely connected with the thyristor; the diode is selected so that its avalanche voltage (VBR) is lower than the break-over voltage of the thyristor and gets higher only for overvoltages having a higher duration or amplitude than a predetermined threshold.