Temperature compensated current reference circuit

摘要

A temperature compensated current reference circuit has a differential amplifier and a first feedback transistor with a gate coupled to the differential amplifier output. The first feedback transistor couples a supply voltage line to an inverting input of the differential amplifier. There is also a second feedback transistor with a gate coupled to the differential amplifier output, which couples the supply voltage line to a non-inverting input of the differential amplifier. A first temperature dependent conductor couples the inverting input to ground. A primary reference resistor and a second temperature dependent conductor are connected in series and couple the non-inverting input to ground. An output current control transistor has a gate and one other electrode coupled together and a third electrode coupled to the supply voltage line. A secondary reference resistor and a conductivity change sensing transistor are connected in series and couple the gate of the output current control transistor to ground. The conductivity change sensing transistor has a gate coupled to the second one of the two differential inputs. There is a temperature compensation current reference output circuit that has a current reference transistor, an input coupled to the differential amplifier output and another input is coupled to the gate of the output current control transistor.