Baseplate is a unit mechanically fixed to drawer mounting rail. All the outgoing/incoming wires of the MCU (except main currents and PTC) are connected to Baseplate. Main Unit and Current Measurement Unit are plugged to Baseplate.

Fig. 2 shows the conventional ESD protection design with dual diodes (DPand DN) at RF I/O pad and the power-rail ESD clamp circuit between VDDand VSS[3]. Under positive-to-VDD (PD) or negative-to-VS