A switchable current source, comprising: - an input current path with a controllable current source to feed a changeable current (Itrim) to the input current path, the input current path being configured to provide a reference voltage (VREF) being dependent on the changeable current (Itrim), - an output terminal (LDR_PIN) to provide an output current (ILDR), - an output current path to provide an output current (ILDR), the output current path being connected to the output terminal (LDR_PIN) and being configured to convert the output current (ILDR) into a sensing voltage (VSENS), - a regulator circuit having a first input terminal (E1_RC) to apply a first input signal (VPOS) and a second input terminal (E2_RC) to apply a second input signal (VNEG) and an output terminal (O_RC) to provide an output signal (VOUT2), wherein the regulator circuit is arranged to provide the output signal (VOUT2) in dependence on a comparison of the first and second input signals, - a controllable output driver being controlled in dependence on the output signal (VOUT2), wherein the controllable output driver is arranged to change the output current (ILDR) in dependence on the output signal (VOUT2), - a feedback path coupled between the output current path and the first input terminal (E1_RC), - wherein the regulator circuit comprises a first amplifier and a second amplifier, - wherein the first amplifier has an input side (I_AMP1) including the first and second input terminals (E1_RC, E2_RC) and an output side (O_AMP1) to provide a comparing signal (VOUT1), the first amplifier being arranged to compare the first and second input signal (VPOS, VNEG) of the regulator circuit and to provide the comparing signal (VOUT1) in dependence on the comparison of the first and second input signals (VPOS, VNEG) of the regulator circuit, - wherein the second amplifier has an input side (I_AMP2) to apply the comparing signal (VOUT1) and an output side (O_RC) to provide the output signal (VOUT2), - a switching circuit being configured to operate the switchable current source in a first and a second state, - wherein, in the first state, the switching circuit electrically couples the reference voltage (VREF) to the first input terminal (E1_RC) and the second input terminal (E2_RC) of the regulator circuit and electrically couples a supply potential (VOUT1_CLAMP) to the input side (I_AMP2) of the second amplifier, and, - wherein, in the second state, the switching circuit electrically couples the sensing voltage (VSENS) to the first input terminal (E1_RC) of the regulator circuit and electrically couples the reference voltage (VREF) to the second input terminal (E2_RC) of the regulator circuit and electrically separates the supply potential (VOUT1_CLAMP) from the input side (I_AMP2) of the second amplifier. - an input current path with a controllable current source to feed a changeable current (Itrim) to the input current path, the input current path being configured to provide a reference voltage (VREF) being dependent on the changeable current (Itrim), - an output terminal (LDR_PIN) to provide an output current (ILDR), - an output current path to provide an output current (ILDR), the output current path being connected to the output terminal (LDR_PIN) and being configured to convert the output current (ILDR) into a sensing voltage (VSENS), - a regulator circuit having a first input terminal (E1_RC) to apply a first input signal (VPOS) and a second input terminal (E2_RC) to apply a second input signal (VNEG) and an output terminal (O_RC) to provide an output signal (VOUT2), wherein the regulator circuit is arranged to provide the output signal (VOUT2) in dependence on a comparison of the first and second input signals, - a controllable output driver being controlled in dependence on the output signal (VOUT2), wherein the controllable output driver is arranged to change the output current (ILDR) in dependence on the output signal (VOUT2), - a feedback path coupled between the output current path and the first input terminal (E1_RC), - wherein the regulator circuit comprises a first amplifier and a second amplifier, - wherein the first amplifier has an input side (I_AMP1) including the first and second input terminals (E1_RC, E2_RC) and an output side (O_AMP1) to provide a comparing signal (VOUT1), the first amplifier being arranged to compare the first and second input signal (VPOS, VNEG) of the regulator circuit and to provide the comparing signal (VOUT1) in dependence on the comparison of the first and second input signals (VPOS, VNEG) of the regulator circuit, - wherein the second amplifier has an input side (I_AMP2) to apply the comparing signal (VOUT1) and an output side (O_RC) to provide the output signal (VOUT2), - a switching circuit being configured to operate the switchable current source in a first and a second state, - wherein, in the first state, the switching circuit electrically couples the reference voltage (VREF) to the first input terminal (E1_RC) and the second input terminal (E2_RC) of the regulator circuit and electrically couples a supply potential (VOUT1_CLAMP) to the input side (I_AMP2) of the second amplifier, and, - wherein, in the second state, the switching circuit electrically couples the sensing voltage (VSENS) to the first input terminal (E1_RC) of the regulator circuit and electrically couples the reference voltage (VREF) to the second input terminal (E2_RC) of the regulator circuit and electrically separates the supply potential (VOUT1_CLAMP) from the input side (I_AMP2) of the second amplifier.