Novel Capacitor-less LDO Design Achieves Significant Improvement in Transient Performance

A recent study published in the Electronics journal has proposed a novel on-chip capacitor-less Low-Dropout Regulator (LDO) design, implemented in an SMIC 0.18 μm CMOS process. The research, conducted by a team of engineers from Beihang University, aims to improve the transient response performance of LDOs, a critical challenge in integrated voltage regulator technology.

This innovative design leverages the body effect to enhance driver control without complex bulk-driven techniques, resulting in a quiescent current of 4.5 μA, an efficiency of 88%, an overshoot/undershoot of 12mV/22mV, and a settling time of 1.2 μs. The comparative analysis confirms that this structure increases the maximum load current and reduces the loop response time relative to conventional LDOs.

Key Takeaways:

• The proposed LDO design achieves a significant improvement in transient performance, marking an important advance in integrated voltage regulator technology.
• The fast response loop between the PMOS driver's body and gate leverages the body effect to enhance driver control without complex bulk-driven techniques.
• The LDO design achieves a quiescent current of 4.5 μA, an efficiency of 88%, an overshoot/undershoot of 12mV/22mV, and a settling time of 1.2 μs.
• The comparative analysis confirms that this structure increases the maximum load current and reduces the loop response time relative to conventional LDOs.
• This research validates a significant improvement in the transient performance, making it an important contribution to the field of integrated voltage regulator technology.
• The proposed LDO design has been implemented in an SMIC 0.18 μm CMOS process.
• Beihang University researchers Yuxin Li, Shijindian Tang, Xiao Zhao, and Yanlong Liu, led the research study.

Statistics:

• Quiescent current: 4.5 μA
• Efficiency: 88%
• Overshoot/undershoot: 12mV/22mV
• Settling time: 1.2 μs
• Maximum load current increase: compared to conventional LDOs
• Loop response time reduction: compared to conventional LDOs

Sources:

• "Capacitor-less Ldo With Fast Transient Response Implemented Via Bulk-driven Technique." Electronics, vol. 14, no. 18, 2025, p. 3617. DOI: 10.3390/electronics14083617
• NewsRx. "New Findings from Beihang University Update Understanding of Electronics (Capacitor-less Ldo With Fast Transient Response Implemented Via Bulk-driven Technique)." Journal of Engineering, 20 Oct. 2025, p. 1773.