A Fast-Response BUCK Converter with Adaptive Detect and Transient Enhancement Techniques

This paper presents a fast-response BUCK converter with adaptive transient detect technique (ATDT) and transient enhancement technique (TET). In order to reduce output overshoot and undershoot voltages and achieve shorter recovery time after load change, an adaptive transient detect module is adopted to determine one-shot transient response time, duty cycle will be set to 100% or 0% instantaneously and regulation speed of compensation capacitor voltage will be also enhanced during this time. Besides, oscillation issue is effectively avoided with proposed TET. The presented fast-response BUCK has been implemented in a 0.35μm BCD process, whose verified results are provided to demonstrate the stability and fast response of proposed converter. Compared with conventional BUCK converter, the transient response time is speeded up by more than 2.4X, and the overshoot voltage is shrunk by 0.64X while achieving 0.42X undershoot voltage.

[1]  Ashis Maity,et al.  10.7 A 25MHz 4-phase SAW hysteretic DC-DC converter with 1-cycle APC achieving 190ns tsettle to 4A load transient and above 80% efficiency in 96.7% of the power range , 2017, 2017 IEEE International Solid-State Circuits Conference (ISSCC).

[2]  Jeongjin Roh,et al.  High-performance error amplifier for fast transient DC-DC converters , 2005, IEEE Transactions on Circuits and Systems II: Express Briefs.

[3]  Rui P Martins,et al.  Two Stage Operational Amplifiers: Power and Area Efficient Frequency Compensation for Driving a Wide Range of Capacitive Load , 2011, IEEE Circuits and Systems Magazine.

[4]  Chien-Hung Tsai,et al.  Fast transient current mode dc-dc converter with optimized loop response , 2015, 2015 IEEE 2nd International Future Energy Electronics Conference (IFEEC).

[5]  Dongsheng Ma,et al.  4.2 A 6A 40MHz four-phase ZDS hysteretic DC-DC converter with 118mV droop and 230ns response time for a 5A/5ns load transient , 2014, 2014 IEEE International Solid-State Circuits Conference Digest of Technical Papers (ISSCC).

[6]  Ke-Horng Chen,et al.  Fast Transient (FT) Technique With Adaptive Phase Margin (APM) for Current Mode DC-DC Buck Converters , 2012, IEEE Transactions on Very Large Scale Integration (VLSI) Systems.

[7]  Ke-Horng Chen,et al.  Adaptive Pole-Zero Position (APZP) Technique of Regulated Power Supply for Improving SNR , 2008, IEEE Transactions on Power Electronics.

[8]  Ke-Horng Chen,et al.  Fast Transient DC-DC Converter with On-Chip Compensated Error Amplifier , 2006 .

[9]  Yasuo Unekawa,et al.  4.1 A 3-phase digitally controlled DC-DC converter with 88% ripple reduced 1-cycle phase adding/dropping scheme and 28% power saving CT/DT hybrid current control , 2014, 2014 IEEE International Solid-State Circuits Conference Digest of Technical Papers (ISSCC).

[10]  Mi Zhou,et al.  A Fast Transient Response DC-DC Converter with an Active Compensation Capacitor Module , 2018, 2018 IEEE International Symposium on Circuits and Systems (ISCAS).

[11]  H. Sakurai,et al.  A CMOS Current-mode DC-DC converter with input and output voltage-independent stability and frequency characteristics utilizing a quadratic slope compensation scheme , 2007, ESSCIRC 2007 - 33rd European Solid-State Circuits Conference.