A power supply arrangement has a charge storage means, a charge means, a reference signal source and a processing means. The power supply arrangement is implemented to provide the output signal with the predetermined output signal level at the output terminal based on the supplementary supply signal or based on a combination of the supplementary supply signal and the input signal, if the actual input signal level is lower in amount to the set input signal level. The power supply arrangement can be used in a side airbag sensor system, wherein a power supply and communication protocol is used, which transmits an input signal in the form of a transmitted pulse to a sensor via the voltage supply, to store energy based on the transmitted pulse and to use the same to maintain an output level at the output of the voltage supply, when the input voltage falls below a critical threshold.