RDA8420T is the BMA8420 reference design, created to accelerate the development and prototyping of battery junction box (BJB) systems for automotive and industrial applications. The BMA8420 is a battery junction box controller integrated circuit (IC) that provides ASIL D-capable current measurement, electrochemical impedance spectroscopy (EIS), high accuracy voltage sensing and pyrotechnic switch control, enabling safe and intelligent battery management architectures. This reference design showcases a typical BMA8420 application that meets automotive constraints and system requirements. Communication is delivered through an isolated daisy-chain interface, simplifying integration into high-voltage battery packs.