A 1Mrad Rad-Hard 20mA Linear Regulator for Deep Space in Standard 180nm CMOS Process

This work presents two radiation-hard LDO regulators (one with PMOS and the other with NMOS power transistor) implemented in a standard 180 nm CMOS technology by X-Fab, delivering a programmable voltage output (1 V, 1.2 V or 1.8 V) with up to 20 mA load current and a dropout voltage for the PMOS of ~150 mV. The design also includes a trimmable bandgap reference based on current-mode approach. The design employs radiation-hardened layout techniques both at architecture and layout levels (i.e., ELT and guard rings) starting from a conventional topology. They integrate a current monitor feature, as well. Stability is ensured via external compensation, different for the two LDOs, enabling adequate transient response. Experimental results in lab demonstrate performance comparable to commercial LDOs. The LDOs have been characterized also under radiation featuring a robustness over 1 Mrad (Si) for TID with very limited output voltage degradation. The power consumption shows a negligible increase, too. In heavy ions experiment at the facility of University of Jyvaskyla no SEL has been observed for energy up to 60 MeVcm2/mg (Xenon).