Abstract: A circuit arrangement for generating charge pulses during digital telecommunications is indicated, whereby subscribers (Tln) of a telephone network are connected by cables with an exchange. The subscriber telephones are connected by electric service lines to an interface unit that is connected to the exchange. The interface unit has a digital interface on the exchange side and at least one analog interface on the subscriber side. A generating circuit (3) is located in the interface unit and produces charge pulses as a function of signals transmitted by the exchange, the charge pulses being transmitted to the respective subscriber (Tln). When loop current flows through the electric circuit of each subscriber (Tln) telephone, the interface unit measures an input voltage that is proportional to the length of the service line. The thus gained voltage value is used to adjust the voltage level of the charge pulses produced by the generating circuit (3).