A circuit arrangement, comprising: a first branch comprising: a terminal for a supply potential ; a resistor of variable resistance ; a bipolar transistor connected as a diode; a terminal for ground potential connected to the bipolar transistor ; a second branch , comprising: a resistor of fixed resistance , the resistor of fixed resistance connected to the resistor of variable resistance of the first branch ; another bipolar transistor connected as a diode, the terminal for ground potential connected to the other bipolar transistor ; a control loop configured to reproduce a voltage drop at the resistor of variable resistance to a voltage drop at the resistor of fixed resistance , the control loop , comprising: a transistor disposed in the second branch ; an amplifier having input terminals (-, +) connected to the resistors of the first and second branches (101, 103, 104; 102) and having an output terminal to control the transistor of the second branch , wherein the transistor is controlled such that the difference between the voltages at the input terminals (-, +) of the amplifier becomes substantially zero; a voltage shifter disposed in the first branch and connected between the resistor of variable resistance and the bipolar transistor ; and an output terminal connected to the bipolar transistor of the first branch and another output terminal connected to the other bipolar transistor of the second branch , the output terminals configured to supply a differential voltage (VBE1, VBE2). a first branch comprising: a terminal for a supply potential ; a resistor of variable resistance ; a bipolar transistor connected as a diode; a terminal for ground potential connected to the bipolar transistor ; a terminal for a supply potential ; a resistor of variable resistance ; a bipolar transistor connected as a diode; a terminal for ground potential connected to the bipolar transistor ; a second branch , comprising: a resistor of fixed resistance , the resistor of fixed resistance connected to the resistor of variable resistance of the first branch ; another bipolar transistor connected as a diode, the terminal for ground potential connected to the other bipolar transistor ; a resistor of fixed resistance , the resistor of fixed resistance connected to the resistor of variable resistance of the first branch ; another bipolar transistor connected as a diode, the terminal for ground potential connected to the other bipolar transistor ; a control loop configured to reproduce a voltage drop at the resistor of variable resistance to a voltage drop at the resistor of fixed resistance , the control loop , comprising: a transistor disposed in the second branch ; an amplifier having input terminals (-, +) connected to the resistors of the first and second branches (101, 103, 104; 102) and having an output terminal to control the transistor of the second branch , wherein the transistor is controlled such that the difference between the voltages at the input terminals (-, +) of the amplifier becomes substantially zero; a transistor disposed in the second branch ; an amplifier having input terminals (-, +) connected to the resistors of the first and second branches (101, 103, 104; 102) and having an output terminal to control the transistor of the second branch , wherein the transistor is controlled such that the difference between the voltages at the input terminals (-, +) of the amplifier becomes substantially zero; a voltage shifter disposed in the first branch and connected between the resistor of variable resistance and the bipolar transistor ; and an output terminal connected to the bipolar transistor of the first branch and another output terminal connected to the other bipolar transistor of the second branch , the output terminals configured to supply a differential voltage (VBE1, VBE2). <EOS>