Radiation Hardened, Programmable Battery Analog Front-End ASIC

In response to NASArsquo;s S13.07 SBIR solicitation, Alphacore will develop a radiation-hardened, high accuracy Battery Analog Front-End (B-AFE) Application Specific Integrated Circuit (ASIC) that can implement low-noise, high dynamic range, low-offset offset-drift Coulomb Counting (CC), high precision temperature and terminal voltage measurement embedded with Electrochemical Impedance Spectroscopy (EIS). The B-AFE ASIC will be programmable and flexible to support various energy density (gt;200 Wh/kg and gt;200 Wh/l) and battery state estimation approaches. Alphacore will leverage existing designs and evaluation results to develop a CMOS-based, radiation-hardened (to 1 Mrad total ionizing dose) Coulomb counting Sigma;Delta; ADC-based ASIC. To significantly improve the radiation tolerance, Alphacore will implement the battery monitoring circuitry in the XFAB 180nm high-voltage (HV) silicon-on-insulator (SOI) process. SOI processes are known to provide excellent benefits in terms of SEEs, but TID has been a problem. Alphacore has already fabricated and TID tested three important building blocks of the system, LDO, BGR and Flyback converter and hardness beyond 300krad(Si) was proven. Phase II efforts will focus on layout, integration and CMOS fabricating and testing of the designed CC and EIS system IC, incorporating necessary risk reduction tests, detailed design reviews, and test plans. The principal Phase II deliverable will be a prototype B-AFE system provided to NASA for reliability and durability testing. The CC+EIS concept developed in Phase I will be adapted to full-size cells to assess system capabilities over a dynamic range of charge/discharge cycles. Long-term testing, following NASA ESTA standards, will be employed to evaluate the safety and performance of the full-scale design. During Phases II and III, algorithm development for SoC estimation of Li/CFx primary cell batteries will commence, utilizing direct calculation, model-based, and data-driven approaches. nbsp;