1 Introduction

High accuracy and precision temperature measurements can be easily achieved at low cost with TMP6x linear thermistors using the steps outlined in this application note. As an example, the data in Figure 1-1 shows the average error across temperature for one unit after implementing the methods explained here. The steps to achieve high accuracy with the TMP6x are:

1. Use the 4th order polynomial from the TMP6x Thermistor Design Tool to convert the V_sense voltage to temperature
2. Perform a single-point offset correction to increase accuracy; no temperature chamber or oil bath is needed.
3. Implement oversampling and software filtering to reduce noise and increase measurement precision. Use oversampling and software filtering together for best results.

Figure 1-1 shows the impact of a single-point offset, 32 × oversampling and software filtering with 0.1 alpha on accuracy and precision of one unit across temperature.

Figure 1-1 Temperature Error ±3σ (Noise) Across Temperature

The following sections provide brief descriptions of each individual step, as well as pseudocode to begin evaluating quickly.