Abstract: An input protecting circuit for a semiconductor circuit component having an input terminal, which is powered by a direct current power source, is provided with a series circuit having a first diode connected in series with a biasing element, the series being connected across the direct current power source. The first diode is forward-coupled. A second diode is further provided the second diode being reversely-coupled between a junction of the first diode and the biasing element, and the input terminal of the semiconductor circuit component. This input protecting circuit operates so as to prevent a signal level at the input terminal from being greater than the supply voltage of the direct current power source. An additional first diode and second diode may be provided, the additional first diode being in the series circuit and the additional second diode being associated with the biasing element so as to prevent a positive or negative input signal from being greater than the supply voltage.