Rev. 1.7 3/15

Copyright © 2015 by Silicon Laboratories

AN607

AN607

1. Introduction

This designer's guide describes the Si70xx family of humidity and temperature sensor products in a variety of

different applications. The first half provides a detailed description of the Si70xx family of humidity sensors

including specific application examples. System-level design considerations including sensor placement, system

calibration and product use are discussed. Finally, special handling considerations for both the sensor device and

the end product containing the sensor are discussed.

The second half begins with a brief description of humidity and the various ways it is quantified. It is important to

understand the terminology and the relative merits of each measurement. Next, methods for measuring humidity

and measurement challenges are presented. Finally, the impact of humidity on comfort is discussed.

“ Appendix A—Industry Specifications and Guidelines” contains valuable reference information about industry

standards applicable to the measurement and control of humidity. “ Appendix B—Equations for Vapor Pressure

and Humidity Calculations” contains a description of several equations useful for humidity related calculations. “

Appendix C—Term, Unit, and Coefficient Reference” contains a convenient reference containing unit conversions,

coefficients and a glossary of humidity related terms used in this document. “ Appendix D—Nonlinear Correction of

Voltage Inputs with the Si7013” explains the nonlinear correction of the Si7013 voltage input. “ Appendix E—

Thermal Model for a Sensor on a Paddle” presents a thermal model for a sensor on a paddle.

Figure 1. Si7013 Relative Humidity and Temperature Sensor Shown with and without

Hydrophobic Cover Installed

Figure 2. Si7053/4/5 Temperature Sensor

Figure 3. Si7034 Relative Humidity and Temperature Sensor