The Low-Power Gigabit Transceiver (lpGBT) is a radiation-tolerant ASIC used in high-energy physics experiments for multipurpose high-speed bidirectional serial links. Around 200,000 chips have been tested with a production test system capable of exercising the majority of the ASIC functionality to ensure its correct operation. Furthermore, specific individual qualification tests were carried out beyond the production tester limits, including radiation, multi-drop bus topology, inter-chip communication through different types of electrical links and characterization of jitter and stability of the recovered clocks. In this article, an overview of the production and qualification tests is given together with their results demonstrating the robustness and flexibility of the lpGBT.