A 0.45 mV/V Line Regulation, 0.6 V Output Voltage, Reference-Integrated, Error Amplifier-Less LDO With a 5-Transistor Regulation Core

This article proposes a fully-integrated, error amplifier (EA)-less, reference-inbuilt, dual-loop low dropout regulator (LDO) working at a minimum input voltage of 0.7 V. The reference-integrated structure has a flipped-voltage-follower (FVF) as the output stage and provides an output voltage of 0.6 V. The dual-loop architecture provides high dc loop gain ( $\geq $ 60 dB), a very small output impedance, along with the proposed load-adaptive-biasing (LAB), which results in excellent line and load regulation. The power supply rejection (PSR) of the proposed LDO is improved by $>$ 30 dB at frequencies around 100 kHz, using the proposed replica-based supply noise cancellation (RSNC). The design is fabricated in 0.18 $\mu \text{m}$ CMOS technology and occupies an area of 0.074 mm2. The measured load and line regulation are 0.35 mV/mA and 0.45 mV/V, respectively, which are the best in the literature for sub-1 V LDOs. The minimum PSR till 1 MHz is −41.2 dB, and the design achieves a transient figure of merit (FoM) of 35.82 fs considering the limitation of having a low input voltage at a higher technology. This LDO achieves a 2.78 $\times $ better line regulation and a 1.43 $\times $ better load regulation compared to state-of-the-art sub-1 V LDOs while assuring a strong PSR performance till 1 MHz.