Magnetically switched integrated SCR

The design and performance of a bipolar IC is described, in which a magnetically sensitive lateral p-n-p transistor is applied to the switching of a 25-mA SCR integrated on the same chip. The circuit can be operated from either an ac or dc supply and features an on-chip trim arrangement that allows the threshold magnetic field to be changed by increments of 0.05 (torr), thus providing a means of adjustment against mismatch or misalignment.