Fault-tolerant analogue switches

A new family of analogue-switch ICs provides, what is claimed as, a new solution to an old problem, that of protecting the switch and associated circuitry from overvoltage at the signal and supply-voltage terminals. Overvoltage can occur during power-up and power-down, and in systems for which the signal voltages are independent of the supply voltages. The new approach employs on-chip circuitry that senses a fault condition and then turns the switch off, preventing the fault from propagating through the switch to disrupt other circuitry.