Using the fact that the VRE of a transistor shifts 59.16 mV per decade of current at 25Â°C. This cons
tant is 0.33%/Â°C. This V5E-vs.-current relationship holds true regardless of the FBe absolute value. IC, an LT1043, acts as an oscillator and switches a current source (Ql) at a 10:1 ratio. The stepped 10:1 current drive is translated to temperature by IC2, Q2, and the associated components. Accuracy is Â±1%. No compensation is needed if Q2 is changed.