This paper presents a trimming technique to suppress the thermal effects of process spread of BJT-based temperature processing circuits. The proposed calibration method has the advantage of requiring a reading at a single temperature while compensating for the spread of the thermal behaviour of the base-to-emitter voltage of bipolar transistors; in addition to this, the effectiveness of the proposed technique is improved by an exponential approach carried out on the design of the trimming structure. The strength of this technique is shown to be effective on a 6-bit trimming circuit designed and extensively simulated in a standard 180-nm CMOS process.