an input node, adapted to receive an analog input current;

an integrating capacitor; wherein a first end of the integrating capacitor is coupled to the input node;

a quantizer that comprises a data input, a clock input and an output; wherein the data input is coupled to the input node, the clock input receives a jittered clock signal and the output controls a first switch in response to a voltage level of the input node;

a fast charge transfer circuit, for transferring to the integrating capacitor a fixed charge if the first switch is closed; wherein the fixed charge is being transferred during a charge transfer period that is substantially shorter than a minimal clock signal phase of the jittered clock signal; and

the first switch, coupled between the input node and the fast charge transfer circuit.