1、第29卷第2期 半 导 体 学 报 V0129 No22008年2月 JOURNAL OF SEMICONDUCTORS Feb，2008：=；=；=亍=。22252。2。4A Piecewise Linear Slope Compensation Circuitfor DCDC Converters。Ye Qiang+，Lai Xinquan，Li Yanming，Yuan Bing，and Chen Fuji(Institute of Electronic CADXidian University，Xian 710071，China)Abstract：To prevent sub-harm
2、onic oscillation and improve the stability and load capacity of the system，a piecewise Iinearslope compensation circuit is designedCompared with the traditional design，this circuit provides a compensation signalwhose slope varies from different duty cycles at一4085，and reduces the negative effect of
3、slope compensation on thesystems load capacity and transient responseA current mode PWM Boost DC-DC converter employing this slope cornpensation circuit is implemented in a UMC 06“mBCD processThe results indicate that the circuit works well and effee-tively，and the load capacity is increased by 20。T
4、he chip area of the piecewise linear slope compensation circuit ls0Olmm2，which consumes only 8肛A quiescent current，and the efficiency ranges up to 93Key words：DCDC converter；slope compensation；EEACC：2570P；2570A；2560PCLC number：TN433 Document code：Al Introductionpiecewise linear；duty cycleArticle ID：
5、02534177(2008)020281-07In medium and small power DCDC switchedpower suppliesthe peak currentmode controllingtechnique in constant frequency PWM closed loopfeedback controlling system is widely used to achievebetter dynamic performance，higher precision，largergain bandwidth，and protection from transie
6、nt largecurrentFor the duty cycle D50，there is an inherentopen100p instability and subharmonic oscillation inthe constant frequency peak currentmodeL20 control-ling systemIf the conventional compensation that isstable under all duty cycles including the maximumd id t(the worst condition)promised wit
7、h the con-stant compensation rate is used，then it will Iead to alarge slope compensation and damage the transientresponse characteristic and peak inductor current ofthe switched power supplyEspecially in the unloadconditions，the excessive compensation may make thepeak currentmode controI change into
8、 the voltage-mode control。which is unexpectedTherefore，newcircuits are required that can produce a compensationrate that varies in different duty cycles to solve theseissuesIn this paper。a piecewise 1inear slope compensation is introduced to prevent subharmonic oscillation and stabilize the constant
9、 frequency configurationc23The design we propose can decrease the negativeeffects of the slope compensation to systems load ca-pacityThe duty cycle is divided into three parts，and，in each part，there is a linear compensation signal，which achieves a large peak current and the systemsload capacity，and
10、is stable under high duty cycleThedesign is suitable to boost DCDC converters as wellas buck DCDC converters by adjusting the feedbackvoltage2 Principle of slope compensationFigure 1 shows the principle of slope compensationE 4|，where m，m1，and m20，and A10 is a littledistortionFrom Fig1，we have：龇一龇署焉
11、 (1)It is evident that the condition of the system isstable，which satisfies：m 2一mml+mMoreover，簪：一(一历1)m。(4)Figure 2 shows the function of compensation rateof the duty cycle according to Eq(4)，where m2 satis-fies： m：=(髻)。=(半)一 (5)m 2 is the maximum falling slope of the inductor cur-rent，which is dete
12、rmined by the maximum outputvoltage and minimum inductanceThe compensationrate m is proportional to every increase of duty cycleDFor D=100，ie，m05m2，the system is stable under all conditionsIs胡3 Circuit design31 Piecewise linear slope compensation designFigure 3 presents the boost DcDC block diagram，
13、which consists of such blocks as reference，oscillater，start up and fault control(including softstart，undervoltage lock，overcurrent protection，over-temperature protection and over-voltage protection)，error amplifier，PWM comparator，and driving circuit9The reference block can provide five kinds ofvolta
14、ges，which are 12，08，035，03，and 015VThe chip has a peak current threshold of 3A and anoscillation frequency of 1 MHzThe under voltagel彳暑善罚ADuty cycleFig4 Current of slope compensationlock block acts when the power supply is lower than20V and makes the chip cut down to prevent unstable operationThe sl
15、ope compensation block can produce a slope compensation signalThis signal will beadded to the inductor current sampling signal，whichwill be further compared with the signal produced bythe error amplifier to secure the inductor current peaktesting signalFor the whole chip，the duty cycle can be divide
16、dinto three parts to make piecewise linear compensationBy Eq(4)，for D30in the designFor F(Q1)0 and F(Q2)0 and F(Q2)0，both Q1 and Q2are onIt enters the third part D2100，that is，VI，+y2y啪111400 65O10”。P-TimeitsFig。7 Linear versu$piecewise linear slope currenty一队=Vsisma=IswRDSON+mlopeDT(RfV+R SENSE)，0Is
17、wIL咖 (21)The maximum load current of the Boost DCDCis：J一=(LM一警)镖，她=半扣=警，From Eq(21)，we can see that when V一队re-mains constant，the greater m。lope(j。Iope)is，the less lsw(the maximum Isw equals I LIM)isIn order to guarantee current loop stability，the piecewise linear slopecompensation greatly reduced t
18、he negative effects onthe systemS load capacity from Eqs(21)and(22)The simulation results are shown in Fig74 Experimental results41 Entire circuit simulation resultsBased on the UMC 06tmBCD process，the circult is simulated using HspiceFigure 7 shows thesimulation results，which indicate better transi
19、entcharacteristics of the piecewise linear slope compensation currentWhen the duty cycle is D and the system is stable，the current of piecewise linear slopecompensation is less than that of linear slope compensationWe can derive that the adoption of piecewiselinear slope compensation degrades the ef
20、fect of theTable 1 Electrical characteristics of the chip with the proposedpiecewise slope compensation circuitPower supplyV 25 36 55FrequencyMHz 1 l 1Peak currentA t5 21 3Efficiency 90 92 93RDNn O18 O16 O14D Slope(AS)Temp 60一40 O 429 96325 O 532 11Z85 O 608 119VDD=5VVOUT=9V Linear slope Piecewise l
21、inear slope，oMx 860mA 1036mAFig8 Current slope of compensation versus duty cycle at dif-ferent temperaturesthe duty cycle between 0temperature between40and DMA)(100and atand 8542 Testing results and layoutTO test and verify the chip，the transient responseis tested taking the output wave filtering ca
22、pacitor of47t|F and the 300mA square load current，whose risingand falling time are 1“sWe find that the output voltage pulse is in the range of 100mV at the terminalVouT and there is no ringingFigures 9 and 10 showthe testing resultsThe testing conditions in Fig9 arepeak value of the inductor current
23、 greatly and raisesthe load capacity by 20from Eqs(21)and(22)(see Table 1)The value of the slope current is calculated at different duty cycles according to Eqs(15)and(16)Table 1 shows the electrical characteristics of the chipwith the proposed piecewise slope compensation cir-cuit，which gives the s
24、lope current value in the threeduty cycle part爷at一4025，and 85respectivelyFig9 Output and inductor current。f DC-DC c。nverterFigure 8 is the current slope of compensation underi万方数据286 半导体学报 第29卷Fig10 Experimental results-output of load responseVDD=3V and VouT=781V(VouT can reach the design value of 8
25、V by trimming)and in Fig10 are VDD2 25VVOUT=5V with load current skipping from 0to 300mAThe results show that the piecewise linearslope compensation diminishes the negative effects ofslope compensation on load capacity and the transientresponse of the systemTherefore，while satisfyingsystem stability
26、the piecewise linear slope compensation improved the load transient response characteris-tics and load capacityFigure 1 1 is the boost DCDC layout of the chipwith the proposed piecewise linear slope compensation circuitIt is the piecewise linear slope compcnsation circuit within the block。whose area
27、 is 001 mm2and the quiescent current is only 8弘AFig11 Layout of the chip with the proposed piecewise slopecompensation circuit5 ConclusionBased on the analyses of the slope compensationprinciple，a pmcewlse linear slope compensation clr。cuit is designedI t can produce a piecewise linearslope compensa
28、tion signal by employing the oscillatorand piecewise linear function circuit in the design andlayoutThe test results show that，while system stabilitv is satisfied，the circuit has a better transient response characteristic and load capacity。and realizesthe piecewise linear slope compensation accordin
29、g todifferent duty cycles accuratelyThe proposed designis suitable for the currentmode boost DCDC converters of constant frequency as well as buck DCDCconverters by adjusting the feedback voltageReferences123456789Hua WeiStudy on five PWM feedback control modes of SMPSfor telecommunicationTelecom Po
30、wer Technologies，200118(2)：8(in Chinese)华伟，通信开关电源的五种PWM反馈控制模式研究通信电源技术，2001。18(2)；83Wang Hongyi，Lai Xinquan，Li Yushan，et a1Reducing the slopecompensation effect on the load capacity of DC-DC convertersChinese Journal of Semiconduct,ors。2006，27(8)：1484(in Chinese)王红义，来新泉，李玉山，等减小DCDC中斜波补偿对带载能力的影响半导体学报，
31、2006，27(8)：14843Ridley RA more accurate current mode control modelhttp：focusticornlitmlslupl22slupl22pdfTse C K，Lai Y M，Chow M H L，et al，Control of bifurcation incurrentprogrammed DCDC converters；an alternative viewpointof ramp compensationInternational Conference on Industrial E1ectronics，Control a
32、nd Instrumentation，Nagoya，Japan，2000：2413Redl RNovak IInstabilities in currentmode controlled switching voltage regulatorsPower Electronics Specialists Conference，Boulder，CO，1981：178http：focusticomiitanslualolslual01pdfRazavi BDesign of analog CMOS integrated circuitsTranslatedby Chen Guican，Cheng J
33、un，Zhang Ruizhi，et a1Xian：XianJiaotong University Press。2003：391(in Chinese)毕查德拉扎维模拟CMOS集成电路设计陈贵灿，程军，张瑞智，等译西安：西安交通大学出版社，2003：391Gregorian RIntroduction to CMOS op-amp and comparatorsNew York：John WileySons lnc，1999Ye Qiang，Lai Xinquan，Dai Guoding，et a1Novel driver for class-D audio power amplifierCh
34、inese Journal of Semiconductors2007，28(9)：1477(in Chinese)叶强，来新泉，代国定，等一种新颖的D类音频功率放大器电路半导体学报。2007，28(9)：1477万方数据第2期 Ye Qiang et a1：A Picccwise Linear Slope Compensation Circuit for DC-DC Converters 287一种DCDC全区间分段线性斜坡补偿电路设计叶 强 来新泉 李演明 袁 冰 陈富吉(西安电子科技大学电路CAD所，西安710071)摘要：为了防止亚谐波振荡以及提高系统的稳定性和带载能力，设计了一种伞区
35、间分段线性斜坡补偿电路与传统的设计方法相比，该电路在一4085。C下提供的补偿信号在不同的占空比区间内具有不同的斜率，对三个占空比区间进行分段线性斜坡补偿，有效减小了斜坡补偿对系统带载能力、瞬态响应的负面影响，极大地改善了系统的稳定性和带载能力采用此电路的一款电流模PWM升压型DCDC已在UMC 06pmBCD工艺线投片，测试结果证明分段线性斜坡补偿电路性能良好，带载能力提高了20分段线性斜坡补偿电路芯片面积为001mm2，静态电流消耗仅为8pA，芯片效率高达93关键词：DCDC转换器；斜坡补偿；分段线性；占空比EEACC：2570P+2570A,2560P中图分类号：TN433 文献标识码：
36、A 文章编号：02534177(2008)02028107*西安应用材料创新基金资助项目(批准号：XA-AM一200504)t通信作者Emaii：yeqian94213126coln20070806收到，20070925定稿 2008中国电子学会万方数据一种DC-DC全区间分段线性斜坡补偿电路设计作者： 叶强， 来新泉， 李演明， 袁冰， 陈富吉， Ye Qiang， Lai Xinquan， Li Yanming，Yuan Bing， Chen Fuji作者单位： 西安电子科技大学电路CAD所,西安,710071刊名： 半导体学报英文刊名： JOURNAL OF SEMICONDUCTORS
37、年，卷(期)： 2008,29(2)被引用次数： 8次参考文献(9条)1.华伟 通信开关电源的五种PWM反馈控制模式研究期刊论文-通信电源技术 2001(02)2.王红义;来新泉;李玉山 减小DC-DC中斜波补偿对带载能力的影响期刊论文-半导体学报 2006(08)3.Ridley R A more accurate current mode control model4.Tse C K;Lai Y M;Chow M H L Control of bifurcation in current-programmed DC/DC converters:analternative viewpoint
38、 of ramp compensation 20005.Redl R;Novak I Instabilities in current-mode controlled switc-hing voltage regulators 19816.查看详情7.毕查德拉扎维;陈贵灿;程军;张瑞智 模拟CMOS集成电路设计 20038.Gregorian R Introduction to CMOS op-amp and comparators 19999.叶强;来新泉;代国定 一种新颖的D类音频功率放大器电路期刊论文-半导体学报 2007(09)本文读者也读过(10条)1. 陈富吉.来新泉.李玉山.Ch
39、en Fuji.Lai Xinquan.Li Yushan 一种自适应斜坡补偿电路的设计与实现期刊论文-半导体学报2008,29(3)2. 王红义.来新泉.李玉山.Wang Hongyi.Lai Xinquan.Li Yushan 减小DC-DC中斜坡补偿对带载能力的影响期刊论文-半导体学报2006,27(8)3. 来新泉.郭仲杰.张倩.LAI Xin-quan.GUO Zhong-jie.ZHANG Qian 可提高Buck型DC/DC转换器带载能力的斜坡补偿设计期刊论文-微电子学2007,37(1)4. 薛彦红 降压型DC-DC中自适应斜坡补偿电路的设计学位论文20095. 周泽坤.王锐.
40、张波.ZHOU Ze-kun.WANG Rui.ZHANG Bo 一种自适应斜坡补偿电路期刊论文-电子科技大学学报2007,36(1)6. 王留杰.王松林.来新泉.田锦明.WANG Liujie.WANG Songlin.LAI Xinquan.TIAN Jinming 峰值电流模升压变换器分段线性斜坡补偿设计期刊论文-固体电子学研究与进展2007,27(2)7. 包伯成.许建平.刘中.BAO Bo-cheng.XU Jian-ping.LIU Zhong 开关DC-DC变换器斜坡补偿的稳定性控制研究期刊论文-电子科技大学学报2008,37(3)8. 袁冰.来新泉.叶强.靳钊.李演明.贾新章.
41、YUAN Bing.LAI Xinquan.YE Qiang.JIN Zhao.LI Yanming.JIAXinzhang 电流模降压DC-DC大负载低漏失工作研究期刊论文-固体电子学研究与进展2009,29(3)9. 来新泉.周丽霞.陈富吉.CHEN Fu-ji.Lai Xin-quan.ZHOU Li-xia 升压型DC-DC转换器中的动态斜坡补偿电路设计期刊论文-微电子学2005,35(4)10. 张洪俞.夏晓娟.ZHANG Hong-yu.XIA Xiao-juan 一种基于峰值电流模DC-DC转换器的斜坡补偿电路期刊论文-电子器件2007,30(2)引证文献(9条)1.Li Xia
42、nrui.Lai Xinquan.Li Yushan.Ye Qiang Research and design of a novel current mode charge pump期刊论文-半导体学报 2009(10)2.徐祥柱.王易.陈程.明鑫.贾鲲鹏.张波 一种DC/DC斜坡补偿电路的设计期刊论文-中国集成电路 2011(7)3.Guo Zhongjie.Wu Longsheng.Liu Youbao Design and implementation of adaptive slope compensation incurrent mode DC-DC converter期刊论文-半导
43、体学报 2010(12)4.叶强.来新泉.陈富吉.李演明.袁冰 一种用于TFT-LCD液晶显示的片内门宽调制控制器的设计期刊论文-半导体学报 2008(8)5.Guo Zhongjie.Wu Longsheng.Liu Youbao Design and implementation of adaptive slope compensation incurrent mode DC-DC converter期刊论文-半导体学报 2010(12)6.徐祥柱.王易.陈程.明鑫.贾鲲鹏.张波 一种DC/DC斜坡补偿电路的设计期刊论文-中国集成电路 2011(7)7.代国定.徐洋.李卫敏.胡波 电流模PWM降压DC_DC片内补偿电路的设计实现期刊论文-电子器件 2010(1)8.王辉.王松林.来新泉.郭宝龙.牟在鑫 同步整流降压型DC-DC过零检测电路的设计期刊论文-固体电子学研究与进展 2010(2)9.袁冰.来新泉.叶强.靳钊.李演明.贾新章 电流模降压DC-DC大负载低漏失工作研究期刊论文-固体电子学研究与进展 2009(3)本文链接：http:/
