A charge pulse detecting circuit for detecting charge pulses having a charge pulse width comprising a) a sensing device; b) a sense node; c) an active buffer having an input and an output; d) a recharge device comprising at least one first and second terminals; and e) a noise filter having an input, said noise filter input being connected to said active buffer output, said noise filter comprising a passive high-pass filter (306, 307) having a high-pass transition time, said noise filter comprising a filter resistor and a filter capacitor, said filter resistor and said filter capacitor forming said passive high-pass filter; whereby said sensing device is operatively coupled with said sense node to deliver charge pulses to said sense node; said input of said active buffer is connected to said sense node; said at least one first terminal of said recharge device is connected to said sense node and said at least one second terminal is connected to a fixed DC potential to enable establishing a stable DC potential on said sense node; characterized in that said charge pulse detecting circuit comprises a sense capacitor connected on one end to the sense node and on another end to a sense capacitor DC potential, the active buffer is an open loop type unity gain buffer, while the recharge device is designed so as to have a recharge time at least twice as long as the duration of the charge pulse width, the resistance R hp of the filter resistor, the capacitance C hp of the filter capacitor, the impedance R r of the recharge device and the capacitance C s of said sense capacitor are designed such that the noise reduction factor, approximated by R hp C hp R r C s and indicating the reduction of the noise from said recharge device made by said noise filter is at least two while the charge pulse detecting circuit transmits signal voltage pulses. a) a sensing device; b) a sense node; c) an active buffer having an input and an output; d) a recharge device comprising at least one first and second terminals; and e) a noise filter having an input, said noise filter input being connected to said active buffer output, said noise filter comprising a passive high-pass filter (306, 307) having a high-pass transition time, said noise filter comprising a filter resistor and a filter capacitor, said filter resistor and said filter capacitor forming said passive high-pass filter; whereby said sensing device is operatively coupled with said sense node to deliver charge pulses to said sense node; said input of said active buffer is connected to said sense node; said at least one first terminal of said recharge device is connected to said sense node and said at least one second terminal is connected to a fixed DC potential to enable establishing a stable DC potential on said sense node; characterized in that said charge pulse detecting circuit comprises a sense capacitor connected on one end to the sense node and on another end to a sense capacitor DC potential, the active buffer is an open loop type unity gain buffer, while the recharge device is designed so as to have a recharge time at least twice as long as the duration of the charge pulse width, the resistance R hp of the filter resistor, the capacitance C hp of the filter capacitor, the impedance R r of the recharge device and the capacitance C s of said sense capacitor are designed such that the noise reduction factor, approximated by R hp C hp R r C s and indicating the reduction of the noise from said recharge device made by said noise filter is at least two while the charge pulse detecting circuit transmits signal voltage pulses.