A Compact High-Linearity GaN Monolithically Integrated Multi-Loop Voltage Reference for Extreme Temperature Applications

Conventional electronics for extreme environments are typically restricted to single thermal regimes, limiting the feasibility of monolithic circuits capable of wide-range operation. To address this, this letter reports a monolithic voltage reference implemented in D/E-mode p-GaN HEMT technology for operation from -269 °C (5 K) to 250 °C. Based on impedance analysis of the conventional two-transistor reference, a multi-loop topology utilizing depletion-mode devices is introduced to suppress output line sensitivity and improve interference immunity. Experimental characterization demonstrates a stable 1.45 V output across a wide supply range of 5–56 V, achieving a line sensitivity of 0.003421 %/V and a power supply rejection of -50.46 dB at 100 Hz. These results establish the feasibility of high-stability biasing for monolithic all-GaN systems under extreme thermal conditions.