Signal Strength Indicator

A device is for digitally processing an input signal that is susceptible to variations in signal strength. The signal ( 48 ) is analog to digital converted into a bitstream signal ( 47 ), the bitstream signal representing the input signal by consecutive digital values. The device has a signal strength detection circuit ( 32 ) for generating a control signal indicative for an overload condition in which the signal strength exceeds a input range of the analog to digital converter, e.g. a sigma-delta modulator The signal strength detection circuit detects, in the bitstream signal, a sequence ( 49,50 ) of adjacent and equal digital values, the sequence having at least a predetermined length. The circuit detects the overload condition effectively and fast, avoiding the delay of signal strength detection in a digital processor.