Low voltage bipolar drive circuits

A drive circuit comprising:

• a bipolar transistor differential current mirror having two differential current inputs and two differential current outputs all coupled via respective resistors to a low voltage supply, the differential inputs and outputs constituting differential signal inputs and outputs respectively of the drive circuit;
• a circuit comprising a bipolar transistor having a base supplied with a reference voltage, a collector coupled via a resistor to the low voltage supply, and an emitter coupled via a resistor to a reference potential;
• and
• a bipolar transistor current mirror having a current input coupled to the collector of said bipolar transistor and two current mirror outputs coupled to the differential signal inputs, said circuit and bipolar transistor current mirror serving to stabilize a signal voltage swing at the differential signal outputs.

A drive circuit comprising:

• a bipolar transistor current mirror having a current input and a current output each coupled via a respective resistor to a low voltage supply, the input and output constituting a signal input and output respectively of the drive circuit;
• a circuit comprising a bipolar transistor having a base supplied with a reference voltage, a collector coupled via a resistor to the low voltage supply, and an emitter coupled via a resistor to a reference potential;
• and
• a bipolar transistor current mirror having a current input coupled to the collector of said bipolar transistor and a current mirror output coupled to the signal input, said circuit and bipolar transistor current mirror serving to stabilize a signal voltage swing at the signal output.

A drive circuit comprising:

• a first current mirror circuit comprising first and second bipolar transistors having emitters coupled to a reference potential, bases coupled together and to the collector of the first transistor, and collectors of the first and second transistors constituting a signal input and a signal output respectively and being coupled via respective resistors to a low voltage supply;
• a source of a reference voltage;
• a third bipolar transistor having a base supplied with the reference voltage, a collector coupled via a resistor to the low voltage supply, and an emitter coupled via a resistor to a reference potential;
• and
• a compensation current mirror circuit comprising fourth and fifth bipolar transistors having emitters coupled to a reference potential, bases coupled together and to the collector of the fourth transistor, and collectors of the fourth and fifth transistors coupled to the collectors of the third and first transistors respectively.