A 10-MHz 2–800-mA 0.5–1.5-V 90% Peak Efficiency Time-Based Buck Converter With Seamless Transition Between PWM/PFM Modes

Time-based controllers are well suited for implementing both single- and multi-phase wide bandwidth high switching frequency pulsewidth modulation (PWM)-based dc–dc converters. They also consume very little quiescent current but their light load efficiency is severely degraded by switching losses. We explore pulse frequency modulation (PFM) that is commonly used to improve light load efficiency in voltage-mode controllers and extend its operation to time-based controllers. To maintain high efficiency even in the presence of dynamic load variations, we present techniques to perform automatic and seamless switching between PWM/PFM modes. Fabricated in a 65-nm CMOS, the prototype buck converter using the time-based PWM/PFM control achieves 90% peak efficiency and >80% efficiency over a load current range of 2–800 mA. Output voltage changes by less than 40 mV during PWM to PFM transitions.

[1]  Vivek De,et al.  A 500 MHz, 68% efficient, fully on-die digitally controlled buck Voltage Regulator on 22nm Tri-Gate CMOS , 2014, 2014 Symposium on VLSI Circuits Digest of Technical Papers.

[2]  Luca P. Carloni,et al.  A 2.5D integrated voltage regulator using coupled-magnetic-core inductors on silicon interposer delivering 10.8A/mm2 , 2012, ISSCC.

[3]  Cheng Huang,et al.  A 100 MHz 82.4% Efficiency Package-Bondwire Based Four-Phase Fully-Integrated Buck Converter With Flying Capacitor for Area Reduction , 2013, IEEE Journal of Solid-State Circuits.

[4]  Seth R. Sanders,et al.  A 4-μA quiescent-current dual-mode digitally controlled buck converter IC for cellular phone applications , 2004 .

[5]  Amr Elshazly,et al.  High Frequency Buck Converter Design Using Time-Based Control Techniques , 2015, IEEE Journal of Solid-State Circuits.

[6]  Mei-Ling Yeh,et al.  A High Efficiency Dual-Mode Buck Converter IC For Portable Applications , 2008, IEEE Transactions on Power Electronics.

[7]  Bertan Bakkaloglu,et al.  A 300mA 14mV-ripple digitally controlled buck converter using frequency domain ΔΣ ADC and hybrid PWM generator , 2010, 2010 IEEE International Solid-State Circuits Conference - (ISSCC).

[8]  S. Narendra,et al.  A 233-MHz 80%-87% efficient four-phase DC-DC converter utilizing air-core inductors on package , 2005, IEEE Journal of Solid-State Circuits.

[9]  Woo-Seok Choi,et al.  A 10MHz 2mA-800mA 0.5V-1.5V 90% peak efficiency time-based buck converter with seamless transition between PWM/PFM modes , 2017, 2017 IEEE Custom Integrated Circuits Conference (CICC).

[10]  Wing-Hung Ki,et al.  A 10/30 MHz Fast Reference-Tracking Buck Converter With DDA-Based Type-III Compensator , 2014, IEEE Journal of Solid-State Circuits.

[11]  O. Garcia,et al.  Automotive DC-DC bidirectional converter made with many interleaved buck stages , 2006, IEEE Transactions on Power Electronics.

[12]  Pavan Kumar Hanumolu,et al.  A 4-Phase 30–70 MHz Switching Frequency Buck Converter Using a Time-Based Compensator , 2015, IEEE Journal of Solid-State Circuits.

[13]  O. Garcia,et al.  Current Self-Balance Mechanism in Multiphase Buck Converter , 2009, IEEE Transactions on Power Electronics.

[14]  R. Bashirullah,et al.  A Delay-Locked Loop Synchronization Scheme for High-Frequency Multiphase Hysteretic DC-DC Converters , 2007, IEEE Journal of Solid-State Circuits.

[15]  Robert W. Erickson,et al.  DC-DC converter design for battery-operated systems , 1995, Proceedings of PESC '95 - Power Electronics Specialist Conference.