An Enhanced Start-up Circuit Eliminating All Trojan States in Self-biased Reference Generators

A self-biased voltage/current reference (VCR) generator is simple, but suffers from some Trojan states surviving the conventional start-up process. After demonstrating this problem by simulation, this paper reveals the mechanism by identifying and analyzing all of the feedback loops that give rise to multiple Trojan states. Based on the theory, an enhanced start-up circuit is proposed that is capable of removing all Trojan states. Finally, the enhanced start-up circuit is embedded into a self-biased voltage reference generator, and designed in 28 nm CMOS process. The simulation results prove that the enhanced start-up circuit successfully eliminates all Trojan states in a wide temperature range for different process corners.