1 Introduction

The solar system includes a lot of end equipment, such as string inverters, hybrid inverters, PCS, and so on. Current sensing is a critical function to the solar system because the measurement accuracy and reliability determines the control accuracy of the power stage and further affects the energy harvest efficiency.

Traditionally, open-loop through-hole board mount Hall-effect current sensors are widely used because the sensors have intrinsic isolation nature, and the non-intrusive measurement also provides wiring and installation convenience. However, open-loop through-hole hall-effect current sensors usually cannot achieve high accuracy over both lifetime and temperature. Meanwhile, failing is simple during the installation and transportation processes due to the brittle magnetic core damage, which reduces the system reliability.

The new trend in the solar system is to use in-package hall-effect current sensors to replace the traditional thorough-hole one. TI’s in-package hall-effect current sensor, such as TMCS112x, TMCS113x and TMCS114x can provide high accuracy combined with low drift, enabling accurate current measurements over both lifetime and temperature. Additionally, the in-package design also provides a compact design without sacrificing isolation performance and without adding system complexity or cost.

There are some key points that must be considered when using in-package Hall-effect current sensors in solar systems. Topics of current ratings and thermals, accuracy, bandwidth, response time and propagation delay, lightning and surge, isolation and reliability are discussed in detail in this application note.