Relationship Between Latchup And Transistor Current Gain

Theoretical study takes new look at current-vs.-voltage behavior of silicon controlled rectifiers (SCR's), four-layer complementary metal oxide/semiconductor (CMOS) devices, and similar devices susceptible to latchup. For purposes of analysis, "latchup" denotes transition of such device from lower-current-conducting steady state to distinct higher-current-conducting steady state. Focuses upon conventional two-couple-transistor model of one-dimensional SCR. Although model gives oversimplified view of latchup in CMOS circuits, useful for qualitative predictions of electrical characteristics.