Patent ID: 8471621

Claim:
Circuit comprising an input means configured to selectively receive a current from a plurality of currents; a first current mirror with mirror ratio m; a second current mirror; a third current mirror; a cross-multiplexer; a differential capacitive transimpedance amplifier having a first capacitance and a first switching element connected in parallel to a negative input port and a first output port of the differential capacitive transimpedance amplifier and a second capacitance and second switching element connected in parallel to a positive input port and a second output port of the differential capacitive transimpedance amplifier; the input means being connected to an input port of the first current mirror; an output port of the first current mirror being connected to input ports of the second and third current mirror; an output port of the second current mirror being connected to a first input port of the cross-multiplexer; an output port of the third current mirror being connected to a second input port of the cross-multiplexer; a first output port of the cross-multiplexer being connected to the negative input port of the differential capacitive transimpedance amplifier and a second output port of the cross-multiplexer being connected to the positive input port of the differential capacitive transimpedance amplifier; the cross-multiplexer being configured either to establish a first current path between its first input port and its first output port and a second current path between its second input port and its second output port in direct mode or to establish a first current path between its first input port and its second output port and a second current path between its second input port and its first output port in reverse mode.