Current source circuit

A current source circuit comprising:

• a differential amplifier including at least a first and a second transistor for amplifying a difference in voltage applied to each transistor base, the voltage difference being output from a collector of said first transistor as an output current;
• a first voltage control circuit including at least one first PN junction connected between a reference potential and said first transistor base, said reference potential being applied to said first PN junction to cause a first voltage drop across said PN junction, the first voltage drop being applied to said first transistor base;
• a second voltage control circuit including at least one second PN junction connected between said reference potential and said second transistor base, the reference potential being applied to said second PN junction to cause a second voltage drop across said second PN junction, the second voltage drop being applied to said second transistor base,
• wherein a first number of PN junctions including a PN junction of said first transistor and the PN junction included in said first voltage control circuit is equivalent to a second number of PN junctions including a PN junction of said second transistor and the PN junction included in said second voltage control circuit;
• a first constant current circuit for supplying a first current proportional to the output current flowing in said differential amplifier, to said first voltage control circuit;
• and
• a second constant current circuit for supplying a second current proportional to the output current flowing in said differential amplifier and different from said first current to said second voltage control circuit.