An integrated circuit preferably to be connected to a motor vehicle
battery is selectively switchable between sleep and normal operating
modes. The IC may include a useful control logic circuit, a wake-up
circuit evaluating an input signal and responsively outputting a wake-up
signal dependent on the input signal, and an input control and supply
circuit connected between the wake-up circuit and the control logic
circuit. The wake-up circuit includes at least one recognition circuit
having an amplifier arrangement to selectively amplify the input signal,
and an evaluation circuit having a switch arrangement controlled by the
amplified signal and an amplifier producing the output signal. The
wake-up circuit has a very low current consumption while monitoring the
input signal, and produces the wake-up signal only if the input signal
suitably exceeds or falls below a specified voltage threshold. The
wake-up signal may activate the control circuit, which may activate the
logic circuit.