Latch-up is an undesirable, high current, state that can significantly reduce
the lifetime of a part or cause permanent damage and failure.
Junction-isolated CMOS switches exhibit a silicon-controlled rectifier (SCR)
circuit when the parasitic junction diodes become forward biased. With trench
isolation technology, each N-well and P-well is physically separated by an
insulating oxide layer and the parasitic diode is removed. This results in a
switch that is immune to latch-up under all conditions.