System Co-Design of a High Current (40A) Synchronous Step-Down Converter in an Innovative Multi-chip Module (MCM) LQFN-Type Packaging Technology

The drive for multi-chip module (MCM) packaging technology essentially stems from the ever-increasing demand for miniaturization of power electronics. While promising, MCM packaging technologies present considerable design challenges (viz. electrical, thermal, reliability and manufacturing/assembly) if system co-design techniques are not adopted early in the design process. In this paper we present the electrical system co-design and measurement validation results of a high-efficiency, single channel, integrated FET, synchronous buck converter packaged in a 40-pin 7.00mm × 5.00mm MCM-in-LQFN-type innovative package. Due to the complex 3D level of integration of the monolithic control, drive circuitry, and the two discrete N-channel NexFETTM power MOSFETs, electromagnetic interactions, between die, package, and PCB, are exacerbated with potential impact to system-level performance. We detail here how optimization of the system, was achieved through a coupled circuit-to-electromagnetic co-design modeling and simulation methodology. Laboratory measurements on an integrated high current (40A) synchronous step-down converter are presented that validate the integrity of the co-design modeling and simulation methodology.