Device for operating a passive infrared detector of the two-pole type, said device comprising - a first and a second input transistor (T 1, T 2) each comprising a control input, a first contact and a second contact, - a controllable current divider (MUX, R mi to R mn) comprising a control input (Val) and two current divider outputs (I a1, I a2), - a reference current source (I ref) and - a comparator, characterized in that said device further comprises - a discharge network (R G), - two integrating filters and/or two capacitors (C 1, C 2) and - a digital integrating filter (Int), wherein - each of the outputs of said passive infrared detector is connected to the discharge network (R G), - each of the outputs of said passive infrared detector is connected to the control input of a respectively assigned input transistor of the two input transistors (T 1, T 2), - respectively the first contact of each of said input transistors (T 1, T 2) is connected to one of the current divider outputs (I a1, I a2) of the controllable current divider (MUX, R mi to R mn), - the current divider (MUX, R mi to R mn) is operative to divide a current of the reference current source (I ref) among the current divider outputs (I a1, I a2) in dependence on an input value at the control input (Val), - the second contacts of the transistors (T 1, T 2) are respectively connected to one of the two integrating filters and/or two one of the two capacitors (C 1, C 2), - the output values of said integrating filters and/or said capacitors (C 1, C 2) are compared to each other by the comparator, - a comparator output signal of said comparator is supplied to the digital integrating filter (Int) as an input signal, and - the control input (Val) of the current divider (MUX, R mi to R mn) which divides the current of the reference current source (I ref) is directly or indirectly dependent on the numerical value of an output signal of the digital integrating filter (Int). - a first and a second input transistor (T 1, T 2) each comprising a control input, a first contact and a second contact, - a controllable current divider (MUX, R mi to R mn) comprising a control input (Val) and two current divider outputs (I a1, I a2), - a reference current source (I ref) and - a comparator, - a discharge network (R G), - two integrating filters and/or two capacitors (C 1, C 2) and - a digital integrating filter (Int), - each of the outputs of said passive infrared detector is connected to the discharge network (R G), - each of the outputs of said passive infrared detector is connected to the control input of a respectively assigned input transistor of the two input transistors (T 1, T 2), - respectively the first contact of each of said input transistors (T 1, T 2) is connected to one of the current divider outputs (I a1, I a2) of the controllable current divider (MUX, R mi to R mn), - the current divider (MUX, R mi to R mn) is operative to divide a current of the reference current source (I ref) among the current divider outputs (I a1, I a2) in dependence on an input value at the control input (Val), - the second contacts of the transistors (T 1, T 2) are respectively connected to one of the two integrating filters and/or two one of the two capacitors (C 1, C 2), - the output values of said integrating filters and/or said capacitors (C 1, C 2) are compared to each other by the comparator, - a comparator output signal of said comparator is supplied to the digital integrating filter (Int) as an input signal, and - the control input (Val) of the current divider (MUX, R mi to R mn) which divides the current of the reference current source (I ref) is directly or indirectly dependent on the numerical value of an output signal of the digital integrating filter (Int).