Switching stage

A switching stage, comprising:

• a first terminal receiving a first supply potential;
• a second terminal receiving a second supply potential;
• a differential amplifier configuration having two inputs and an output, said differential amplifier configuration being connected to said first and second terminals;
• an emitter follower transistor having a base connected to said output of said differential amplifier configuration, having an emitter and having a collector;
• a controllable current source connected between the emitter of said emitter follower transistor and said first terminal for the first supply potential, said current source having a control input;
• a switching stage output;
• a resistor having a first terminal connected to the emitter of said emitter follower transistor and a second terminal connected to said switching stage output;
• means having a signal output and being connected to the first and second terminals of said resistor and to said terminal for the first supply potential, for supplying a signal at the signal output being dependent on the polarity of a voltage dropping at said resistor;
• the control input of said current source being connected to the signal output of said signal supplying means for controlling said current source to cause a high current to flow when the first terminal of said resistor is at a more negative potential than the second terminal of said resistor and to cause a low current to flow when the first terminal of said resistor is at a more positive potential than the second terminal of said resistor.