A Radiation Hardened, Digitally Controlled Single-Inductor Multiple-Output (SIMO) Buck Regulator

Alphacore will design, fabricate and test a buck DC-DC converter that can directly convert voltages from 5V ndash; 12V down to 900mV, while supporting at least 10A of current to the load. Our goal is 20A load current, a requirement for some of the most powerful FPGAs. The output voltage will be settable between 900mW and 3.3V. In this Phase I program, we will design a digitally controlled, high-efficiency, radiation hard, hybrid GaN/CMOS integrated single module SIMO DC-DC converter to meet these specifications. The developed converter will have a reduced component count, enabling reduced failure modes, lower PCB area and it includes over voltage protection, fault tolerance, load monitoring, and allows control and status monitoring by a remote power system controller. This solution includes all controller circuitry and drivers integrated in a single CMOS ASIC chip, as well as the GaN-based DC-DC converterrsquo;s power stage. The hybrid module will have a very small form factor, namely 20mm x 20mm x 6mm.Alphacorersquo;s SIMO POL converter will utilize CMOS based drivers and controllers for the GaN power stage. The driver and controller would be based on X-FABrsquo;s latest XT018 process, a 0.18 micro;m modular high-voltage SOI technology. It combines the benefit of conventional SOI wafers with Deep Trench Isolation (DTI), those of a state-of-the-art six metal layers 0.18 micro;m process, and localized partial SOI for unique high-voltage super-junction (SJ) power transistors. Unlike traditional high-voltage LDMOS devices from conventional bulk or SOI CMOS processes, the unique high-voltage SJ DMOS power transistors with VDS breakdown voltage of 100V, 140V and 200V offered in XT018 have reduced conduction loss with the same silicon area, such that lower FOM is available for higher efficiency applications. The planar high-voltage SJ DMOS transistor also has significantly better radiation tolerance for both total ionizing dose effects and single event effects.