Citation: 
Chanrong Jiang, Changchun Chai, Chenxi Han, Yintang Yang. A high performance adaptive ontime controlled valleycurrentmode DC–DC buck converter[J]. Journal of Semiconductors, 2020, 41(6): 062402. doi: 10.1088/16744926/41/6/062402
C R Jiang, C C Chai, C X Han, Y T Yang, A high performance adaptive ontime controlled valleycurrentmode DC–DC buck converter[J]. J. Semicond., 2020, 41(6): 062402. doi: 10.1088/16744926/41/6/062402.
Export: BibTex EndNote

A high performance adaptive ontime controlled valleycurrentmode DC–DC buck converter
doi: 10.1088/16744926/41/6/062402
More Information
Abstract
This paper presents an AOTcontrolled (adaptiveontime, AOT) valleycurrentmode buck converter for portable application. The buck converter with synchronous rectifier not only uses valleycurrentmode control but also possesses hybridmode control functions at the same time. Due to the presence of the zerocurrent detection circuit, the converter can switch freely between the two operating modes without the need for an external mode selection circuit, which further reduces the design difficulty and chip area. The converter for the application of high power efficiency and wide current range is used to generate the voltage of 0.6–3.0 V with a battery source of 3.3–5.0 V, while the load current range is 0.05–2 A. The circuit can work in continuous conduction mode with constant frequency in high load current range. In addition, a stable output voltage can be obtained with small voltage ripple. In pace with the load current decreases to a critical value, the converter transforms into the discontinuous conduction mode smoothly. As the switching period increases, the switching loss decreases, which can significantly improve the conversion efficiency. The proposed AOT controlled valley current mode buck converter is integrated with standard 0.18 μm process and the simulation results show that the converter provides wellloaded regulations with power efficiency over 95%. When the circuit switches between the two conduction modes drastically, the response time can be controlled within 30 μs. The undershoot voltage is controlled within 25 mV under a large current hopping range. 
References
[1] Yu J, Hwang I, Kim N. High performance CMOS integrated PWM/PFM dualmode DCDC buck converter. 2017 18th International Scientific Conference on Electric Power Engineering (EPE), 2017, 1[2] Wang L, Lin F J, Cui Q. Dual 3phase buck converter for multicore CPUs power supply in mobile devices. IEICE Electron Express, 2017, 14, 20170045 doi: 10.1587/elex.14.20170045[3] Ma Y, Wang S, Zhang S, et al. A current mode buck/boost DC–DC converter with automatic mode transition and light load efficiency enhancement. IEICE Trans Electron, 2015, E98C, 496 doi: 10.1587/transele.E98.C.496[4] Chen J J, Shen J H, Hwang Y S. Highefficiency fasttransientresponse V2controlled boost converter with small ESR capacitor. Electron Lett, 2013, 49(22), 1402 doi: 10.1049/el.2013.2772[5] Ke X, Sankman J, Ma D. AO2T current mode buck converter with onecycle transient response and sensorless current detection for medical meters. IEEE Applied Power Electronics Conference and Exposition (APEC), 2016[6] Chen X, Zhou G, Zhang K, et al. Improved constant ontime controlled buck converter with high outputregulation accuracy. Electron Lett, 2015, 51(4), 359 doi: 10.1049/el.2014.4261[7] Yan Y, Lee F C, Mattavelli P, et al. I2 average current mode control for switching converters. 2013 IEEE Applied Power Electronics Conference and Exposition  APEC, 2013[8] Chen J J, Hwang Y S, Chen J H, et al. A new fastresponse currentmode buck converter with improved I2controlled techniques. IEEE Trans Very Large Scale Integr (VLSI) Syst, 2018, 26, 903 doi: 10.1109/TVLSI.2018.2796088[9] Redl R, Sun J. Ripplebased control of switching regulatorsan overview. IEEE Trans Power Electron, 2010, 24(12), 2669 doi: Ripplebasedcontrolofswitchingregulatorsanoverview[10] Lee C F, Mok P K T. A monolithic currentmode CMOS DCDC converter with onchip currentsensing technique. IEEE J SolidState Circuits, 2004, 39(1), 3 doi: 10.1109/JSSC.2003.822927[11] Sahu B, RincnMora G A. An accurate, lowvoltage, CMOS switching power supply with adaptive ontime pulsefrequency modulation (PFM) control. IEEE Trans Circuits Syst I, 2007, 54(2), 312 doi: 10.1109/TCSI.2006.887472[12] Nam H, Ahn Y, Roh J. A buck converter with adaptive ontime PFM control and adjustable output voltage. Analog Integr Circuits Signal Process, 2012, 71(2), 327 doi: 10.1007/s1047001198027[13] Qiu Y, Liu H, Chen X. Digital average currentmode control of PWM DC–DC converters without current sensors. IEEE Trans Ind Electron, 2010, 57(5), 1670 doi: 10.1109/TIE.2009.2032130[14] Barrado A, Vazquez R, Lazaro A, et al. Fast transient response with combined linearnonlinear control applied to buck converters. IEEE Power Electronics Specialists Conference, 2002[15] Lee M C, Jing X, Mok P K T. A 14Voutput adaptiveofftime boost converter with quasifixedfrequency in full loading range. IEEE International Symposium of Circuits and Systems (ISCAS), 2011[16] Jing X, Mok P K T, Lee M C. Currentslopecontrolled adaptiveontime DCDC converter with fixed frequency and fast transient response. IEEE International Symposium on Circuits & Systems, 2011[17] Xu Y, Xu J, Xu L, et al. Constant frequency turnon time control dynamic voltage scaling boost converter. International Conference on Communications, 2013[18] Jing X, Mok P K T. A fast fixedfrequency adaptiveontime boost converter with light load efficiency enhancement and predictable noise spectrum. IEEE J SolidState Circuits, 2013, 48(10), 2442 doi: 10.1109/JSSC.2013.2269852[19] Li Q, Lai X, Zhong L. Adaptive currentthreshold detector for an adaptive ontime buck converter at light load. Analog Integr Circuits Signal Process, 2018, 95, 541 doi: 10.1007/s1047001811406[20] Li J, Lee F C. New modeling approach and equivalent circuit representation for currentmode control. IEEE Trans Power Electron, 2010, 25(5), 1218 doi: 10.1109/TPEL.2010.2040123[21] Shi H, Sun Z, Xu Y, et al. Design of the 1.0 V bandgap reference on chip. IEEE International Conference on ASIC, 2016[22] Huang S P, Feng Q Y, University S J. Design of a novel zerocross detection circuit for synchronous buck converter. Chin J Electron Devices, 2014, 37, 408 doi: :10.3969/j.issn.10059490.2014.03.007[23] Yuan B, Lai X Q, Wang H Y, et al. Highefficient hybrid buck converter with switchondemand modulation and switch size control for wideload lowripple applications. IEEE Trans Microwave Theory Tech, 2013, 61(9), 3329 doi: 10.1109/TMTT.2013.2271757[24] Jin Y Y, Xu J P, Zhou G H. Constant ontime digital peak voltage control for buck converter. Energy Conversion Congress & Exposition, 2010, 2030 doi: 10.1109/ECCE.2010.5618100[25] Gildersleeve M, Forghanizadeh H P, Member S, et al. A comprehensive power analysis and a highly efficient, modehopping DC–DC converter. IEEE Asiapacific Conference on ASIC, 2002[26] Huang C, Mok P K T. A 100 MHz 82.4% efficiency packagebondwire based fourphase fullyintegrated buck converter with flying capacitor for area reduction. IEEE J SolidState Circuits, 2013, 48(12), 2977 doi: 10.1109/JSSC.2013.2286545[27] Li P, Xue L, Hazucha P, et al. A delaylocked loop synchronization scheme for highfrequency multiphase hysteretic DC–DC converters. IEEE J SolidState Circuits, 2009, 44(11), 3131 doi: 10.1109/JSSC.2009.2033508[28] Lee B, Song M K, Maity A, et al. 10.7 A 25 MHz 4phase SAW hysteretic DC–DC converter with 1cycle APC achieving 190 ns tsettle to 4 A load transient and above 80% efficiency in 96.7% of the power range. SolidState Circuits Conference, 2017[29] Teh C K, Suzuki A, Yamada M, et al. 4.1 A 3phase digitally controlled DCDC converter with 88% ripple reduced 1cycle phase adding/dropping scheme and 28% power saving CT/DT hybrid current control. IEEE International SolidState Circuits Conference Digest of Technical Papers, 2014 
Proportional views