A high-precision low-voltage low dropout regulator for SoC with adaptive biasing

A high-precision low-voltage low dropout regulator (LDR) using adaptive biasing to extend the loop bandwidth is proposed for system-on-chip power management applications. The multi-stage output-capacitor-free LDR is stabilized by miller compensation and Q-reduction technique to reduce the requirement of minimum load current. By using direct current feedback from a simple current mirror, the adaptively-biased LDR achieves higher loop bandwidth, faster load and line transient responses, higher power supply rejection and lower output impedance. The load and line regulations are also improved. Designed in a standard 0.35µm CMOS technology (Vtn≈ 0.52V and Vtp≈ −0.72V ), the 1.2V input 1.0V output LDR requires a minimum load current of 50µA and delivers a maximum current of 100mA. Both theoretical analysis and simulation results are presented to demonstrate the advantages of the proposed LDR.

[1]  Chi-Ying Tsui,et al.  Adaptively-biased capacitor-less CMOS low dropout regulator with direct current feedback , 2006, Asia and South Pacific Conference on Design Automation, 2006..

[2]  Gabriel A. Rincon-Mora,et al.  A low-voltage, low quiescent current, low drop-out regulator , 1998, IEEE J. Solid State Circuits.

[3]  Ka Nang Leung,et al.  A Low-Dropout Regulator for SoC With $Q$-Reduction , 2007, IEEE Journal of Solid-State Circuits.

[4]  K. Leung,et al.  A capacitor-free CMOS low-dropout regulator with damping-factor-control frequency compensation , 2003, IEEE J. Solid State Circuits.

[5]  Hoi Lee,et al.  Design of low-power analog drivers based on slew-rate enhancement circuits for CMOS low-dropout regulators , 2005, IEEE Transactions on Circuits and Systems II: Express Briefs.

[6]  Ka Nang Leung,et al.  Development of Single-Transistor-Control LDO Based on Flipped Voltage Follower for SoC , 2008, IEEE Transactions on Circuits and Systems I: Regular Papers.

[7]  Wing-Hung Ki,et al.  A 0.9V 0.35 μm Adaptively Biased CMOS LDO Regulator with Fast Transient Response , 2008, 2008 IEEE International Solid-State Circuits Conference - Digest of Technical Papers.

[8]  Tsz Yin Man,et al.  A high precision, output-capacitor-free low-dropout regulator for system-on-chip design , 2008, 2008 IEEE International Symposium on Circuits and Systems.

[9]  Tsz Yin Man,et al.  A High Slew-Rate Push–Pull Output Amplifier for Low-Quiescent Current Low-Dropout Regulators With Transient-Response Improvement , 2007, IEEE Transactions on Circuits and Systems II: Express Briefs.

[10]  Brian Hu,et al.  A Highly Integrated Power Management IC for Advanced Mobile Applications , 2006, IEEE Custom Integrated Circuits Conference 2006.

[11]  Robert G. Meyer,et al.  Analysis and Design of Analog Integrated Circuits , 1993 .