Flexible TFT Read-Out Circuit Blocks for Large Area Sensor Array System Integration Measuring Photovoltaic Modules and Batteries

• Published in: IEEE journal on flexible electronics Vol. 3; no. 7; pp. 334 - 340
• Main Authors: Mojtaba Sadati Faramarzi, Seyed, Papadopoulos, Nikolas, Genoe, Jan, Myny, Kris
• Format: Journal Article
• Language: English
• Published: IEEE 01.07.2024
• Subjects: Analog design; Batteries; Battery charge measurement; battery integration; Current measurement; energy devices; large-area sensor array; low-temperature poly silicon (LTPS); read-out circuits; Sensor arrays; solar modules; Temperature measurement; Temperature sensors; Thin film transistors; thin-film technology
• ISSN: 2768-167X; 2768-167X
• DOI: 10.1109/JFLEX.2024.3433322

Herein, we report the design and characterization of analog building blocks in low-temperature poly silicon (LTPS) thin-film technology. These circuit blocks are targeted to be used as the fundamental elements of read-out circuitry in a large array of sensors integrated inside solar modules and batteries. The circuits presented here show unparalleled performance for applications that require stable operation over temperature ranges and demand low power consumption. We start with single thin-film transistor (TFT) device characterization and study variation and onset voltage change over different temperatures. Afterward, we analyze the performance of a current source designed in LTPS technology. A low-voltage LTPS operational amplifier (OpAmp) with supply voltage as low as 6 V is presented next, and finally, a high-speed latched comparator with low input offset and clock frequency up to 1 MHz is demonstrated. Using these building blocks to create analog interfaces along with sensor arrays integrated in energy devices enables precise sensor measurement resolution in solar modules and batteries.