The fingerboard was designed for test and characterization purposes. The fingerboard has a dimension of 677mils x 942mils (17.2mm x 23.9mm) and an overall thickness of 62mils (1.6mm). The fingerboard has two cutouts (approximately 55mils, or 1.4mm) on either side of the DUT that makes this a good layout to verify the offset error correction algorithm. They are made with Rogers RO4350B dielectric (instead of FR4). The thermal pad is soldered down, but the thermal pad itself is not grounded, it is just a floating copper pad. However, even with these cutouts, the board itself is pretty thick, which led to some heat rise challenges during this process. If a user wants to design a board similar to this, make sure that the board is not too thick.

Table 3-3 and Table 3-4 show the look up tables for the HDC3020 fingerboard. The LUT was generated using 30 HDC3020 devices and were tested between 15°C – 30°C in increments of 5°C and between 10% – 45% RH in increments of 2.5%RH. The look-up tables were generated at 3.3V and 5V, and both were operated at the full power setting. Al the devices were placed in the chamber and the temperature rise was calculated for each temperature and humidity set point.