Reference circuit

摘要

A reference circuit (200') has bipolar transistors (216, 226) providing a voltage difference DELTA V of base-emitter voltages ¦ VBE ¦ and has resistors (210/R1, 220/R2) for adding a current IR1 resulting from DELTA V and a current IR2 resulting from of base-emitter voltage ¦ VBE ¦ of one bipolar transistor (216 or 226) so that a resulting temperature coefficient TCTOTAL of said currents IR1 and IR2 is compensated. The circuit (200') has voltage transfer units (260, 270) which transfer DELTA V to the resistors (210/R1, 220/R2) so that the resistors (210/R1, 220/R2) do not substantially load the bipolar transistors (216, 226). The voltage transfer units (260, 270) have input stages with n-channel FETs. A control unit (241) which is coupled to the bipolar transistors (216, 226) adjusts input voltages ( ¦ VCE ¦ ) at the voltage transfer units (260, 270) to temperature changes, so that the n-channel FETs operate in an active region. The control unit (241) has a voltage source (290) providing a voltage VDS REF which is similary temperature and process depending as a drain-source voltage of the n-FETs.