Discrete validation of a smart power ASIC (SPIC) for a distributed power system

We describe the design and implementation and discrete validation of a high-voltage BCD-technology based smart power integrated circuit (SPIC) design, which is an "one-chip solution" to control, drive, and protect a two-stage distributed power system (DPS). As such, the proposed SPIC achieves higher power density, reduced design-cycle time, and enhanced system reliability. The DPS comprises a front-end AC-DC single-switch power-factor-correction (PFC) converter, which is cascaded with a back-end DC-DC four-switch full-bridge zero-voltage-switching (FBZVS) converter. The current-and the voltage-mode controllers for the PFC and the FBZVS converters, respectively, are integrated into the SPIC. The SPIC can "directly" fire the 2 high-side and 3 low-side devices in the power system. A combination of bootstrap and charge-pump techniques is used to power the gate-drive circuits for the high-side power devices; hence, the duty cycle for a high-side power device is 100% and independent of the turn-on time of the low-side power device in the same leg of the FBZVS converter. Additionally, a more reliable two-stage fault protection scheme is implemented in the SPIC including protection features such as under-voltage lockout, over-current protection, adaptive shoot-through protection, and soft-start capability. This paper illustrates several key experimental results obtained by controlling the DPS using the discrete SPIC to validate the functionalities of the latter and its satisfactory performance.