数位像机电源系统简介.ppt

,按一下以編輯母片標題樣式,項目,1.Digital Camera System Block Diagram,2.Switch Converter System Type,3.Photoflash Controllers,4.AT1452/53Photoflash Capacitor Charger IC,5.DC/DC Switch Controllers for DSC,6.AT1380 DC/DC Converter,7.AT1382A/AT1382B DC/DC Converter,8.AT1386/AT1387/AT1388 DC/DC Converter,9.AT1393 DC/DC Converter,10.AT1202/AT1117,數位相機系統方塊圖,PC Camera控制系統方塊圖,DSP,COMS Sensor,SCR,Photo Flash,Light module,Data buffer,SDRAM,Code Flash,Power Control&,Battery detect&,Data Flash,Option,Key Board,Option,PC Camera 影像資料系統方塊圖,DSP,CMOS Sensor,USB Output,SDRAM,810Bits Data Bus,16 bits Data bus,Data Flash,8 bits Data bus,CCD Camera控制系統方塊圖,DSP,Sensor,Module,Auto,Focus Lens,Photo Flash,Light module,Data buffer,SDRAM,Code buffer,Code Flash,Memory Card&,USB Connector&,CVBS Connector,Power Control&,Battery detect&,Battery Charger,Key Board,LCD Module,CCD&CMOS 影像資料系統方塊圖,DSP,Sensor,Memory card,(CF/SD/MS/SM),TV Out(CVBS)&,USB connector,SDRAM,810Bits Data Bus,16 or 32bits Data bus,Data Bus:,CF:16/8 SD:4/1 MS:4/1 SM:8,TFT LCD Module,CCD&CMOS 電源系統方塊圖,LDO,AT1117,Charger,AT1457,LDO,AT1202,Flash Light,AT1452 AT1453,DC/DC,Converter,AT1380 AT1382,AT1391 AT1395,AT1393 AT1386,87,88,USB Input,(5V/500mA),Battery Input,(1.8V4.2V),3.0v4.2v,System IC,(DSP/SDRAM/Flash.),1.8v/2.5v/3.3v,Flash Capacitor,300v,Focus Motor,3v/5V,LCD,5v/15v/-7.5v,CMOS 3.3v.2.5V,or,CCD 3.3v/15v/-7.5v,Switch Converter System Type,Buck Converter Circuit,(,Step Down):,右圖為Buck Converter 基本線路結構.,此種線路最大特性是輸出電壓永遠小,於輸入電壓,故又稱:,Step Down Converter.,Buck Converter 輸入與輸出關係式為:,CCM:,DCM:,CCM:continuous conduction mode.,DCM:discontinuous conduction mode.,DC/DC,controller,Boost Converter Circuit(Step Up):,右圖為Boost Converter 基本線路結構.,此種線路最大特性是輸出電壓永遠大,於輸入電壓,故又稱:,Step Up Converter.,Boost Converter 輸入與輸出關係式為:,CCM:,DCM:,Sepic Converter Circuit:,右圖為Sepic Converter 基本線路結構.,此種線路最大的特性在於它的輸出電壓,可同時比輸入電壓高或低,而別於 Buck,與 Boost Converter的線路只能純昇壓或純,降壓.,Zeta Converter Circuit:,右圖為Zeta Converter 基本線路結構.,此種線路最大的特性在於它的輸出電壓,可同時比輸入電壓高或低,而別於 Buck,或 Boost Converter的線路只能純昇壓或純,降壓.,Zeta與Sepic於電路選用的最大差異在於,DC/DC Controller 的輸出控制MOSFET,Gate電壓準位.,Flyback Converter Circuit:,右圖為Flyback Converter 基本線路結構.,此種線路最大的特性在於它的輸出電壓,可同時比輸入電壓高或低,而且它的極性,可正可負.,Flyback Converter 輸出電壓高低,極性正負,的關鍵就在於變壓器的繞線比與一二次側,極性,故當一次側的繞線小於二次側時,輸,出為昇壓反之為降壓,此種電路最大的缺點在於整體體積過大,Photoflash Controllers,Description,Vin(max),On/off,Charge ready,Soft start,Auto-discharge,Auto-refresh,Package,AT1450,Photoflash capacitor charger,13,SOP8,AT1452A/B,Photoflash capacitor charger,7,TSSOP8,AT1453A/B,Photoflash capacitor charger,7,TSSOP8,AT1452/AT1453 Photoflash Capacitor Charger,Features:,AT1452,2.5 to 5.5v supply operating rage.,Low current consumption:1mA in operation,50KHz or 100kHz operation frequency.,Built-in maximum duty control.,Push-pull output.,Built-in soft start circuit.,Built-in auto-discharge function.,Built-in auto-refresh function.,AT1453,2.5 to 5.5v supply operating rage.,Low current consumption:1mA in operation,50KHz or 100kHz operation frequency.,Built-in maximum duty control.,Push-pull output.,Built-in soft start circuit.,Built-in auto-discharge function.,系統參考線路:,1.1V,電源系統設計應流程,:,1.決定最大瞬間電流輸入量及電壓值:,因為數位相機是離線電源系統,設計時應考量輸入能量以求系統,穩定.,2.選擇系統充電最高電壓:(選擇充電電容器),閃光燈動作主要是因為電容放電所產生,故閃光大小取決於選擇,的電容容量大小.,3.決定充電時間:,閃光燈模組主要功能是提供即時亮度,故充電時間的長短是一個,重要的決定.因為充電的長短與所需的電流輸入成反比.,當我們有了以上的資料後就可以決定系統的參數值.,parameter,Symbol,Condition,Values,Unit,Min,Typ.,Max,Input Supply Range,Vcc,2,5,5.5,V,Feedback Voltage,V,FB,Ta=25C,1.080,1.100,1.120,V,Frequency,fose,A,40,50,60,kHz,B,90,100,110,kHz,Charger ON/OFF Section,V,ONH,2.0,V,V,ONL,0.8,V,Recommended Operating Conditions,AT1452,AT1453,AT1452/AT1453 Block Diagram,AT1452 Charger Toggling refresh Mode,Note:AT1453 只有Toggle mode,而沒有Auto mode,AT1452 Auto Mode/Toggle Mode Timing Chart,Soft-Start 功能:,主要是利用RC充電原理,以減緩瞬間啟動時的脈衝電流.,Soft-Start Setting:,Soft-Start 波形說明:,參數設定的公式:,1.Duty Setting:,The Duty resistor selection depends on Duty Cycle,choose the component using the following equation:,2.Output Voltage Setting:,3.Photoflash Capacitor Charger Charge Time:,The energy stored in the output capacitor is:,The output power required by the flyback converter to charge the capacitor in a,period of time is:,2,2,2,請注意使用的MOSFET VDSS耐壓值,當想使用在VCC=VBAT=5V時,由於,二次側的反饋,會使得VDS有上昇至40V的Spike,所以使用在這種場合時,可以,1.,選擇耐壓較高的MOSFET or Transistor(AO3400 VDSS=30V),2.,使用Transistor時記得在BASE端加R及C並聯,3.,因為使用在比較高的輸入場合,可以變更T1設計,會使得Spike比較小.,4.,加Snubber 線路(MOSFET D-S間接10,及,0.1uF串聯),*必須VCC=3.3V VBAT已經READY後,SW才能ON,系統才會開始Charge,請參考 page 15 Timing Chart,如果為了防止充電電容於充飽電後會有放電現象我們可以再加一個二極體做隔離用,此時的電阻偵測迴路就需一位至兩個二極體間.,系統設計應注意事項:,DC/DC Switch Controllers for DSC,Description,Output channel,Min Vin(V),Max Vin,(V),Iq,(mA),Short circuit protect,Soft start,On/off,Under voltage detect,Sync.,package,AT1380,1-Boost,1,1.8,13,5.5,8-Pin SOL,AT1380A,1-Boost,1,2.5,15,6,8-Pin SOL,AT1382A,4-Boost,4,1.4,7,2,LQFP48,AT1382B,3-Boost/1-buck,4,1.4,7,2,LQFP48,AT1386,6-Boost,6,1.4,7,3,LQFP48,AT1387,4-Boost/2-buck,6,1.4,7,3,LQFP48,AT1388,5-Boost/1-buck,6,1.4,7,3,LQFP48,AT1393,4-Boost/2-buck,6,1.7,7,3,LQFP48,AT1380 DC/DC Converter,Features:,1.8 to 13V,supply voltage operation range.,Low current consumption:,5mA,in operation,1uA or less in stand-by.,20kHz to 1MHz operation frequency range supply voltage fluctuations by using an external resistor to set the output current.,Totem-pole output.,Built-in soft-start circuit.,Built-in timer latch type short circuit detection and protection(SCP)circuit.,系統參考線路:,0.5V,電源系統設計流程:,1.決定輸入電壓範圍:,因為電池供電的系統輸入電壓範圍是變動且提供之能量固定,故需要預先計算出所能提供,能量範圍,以配合最佳的控制線路及最佳的效率.,2.決定需要幾組電壓及輸出電壓範圍:,因系統IC所需的電壓範圍不同或特殊的規格需求,故設計時就需統計出所需的電壓.,3.考量機構尺寸,一個完整的產品是需要機構與電子控制相互配合,而輕薄短小亦是目前潮流趨勢,所以電,源系統整體體積大小也是重要考量範圍.,4.選用合適的控制線路:,不同的控制線路會有不同的狀況及不同的電氣特性.所以必須預先決定所用的應,用是純昇壓,純降壓或昇降壓.等.,5.選用合適的Switch IC,綜合以上的限制,而選用何種Switch controller IC.,Ex:AT1380,AT1382,AT1386,AT1387.,AT1380 Block Diagram:,0.1v,Function Description:,Soft Start SCP:,當power On 時,AT1380的SCP pin會對電容,充電(1uA),預防電流凸波overshoot狀態.,當AT1380SCP Pin充電達到0.8v時,AT1380,就會從Soft-start 模式進入normal 模式而且,啟動SCP 功能如果輸出負載突然被改變成重,載或短路狀況,則FB Pin 會被固定在VOMax,然後SCP Pin 將小於0.8v,Output Pin 將被設,Low 直到從新開關電源.,Setting Oscillating Frequency:,由,與,T,所組成之三角波產生器,電壓震幅為0.1v0.8v頻率範圍為20KHz1MHz,計算式如下:,AT1382A/AT1382B DC/DC Converter,AT1382A Features:,1.Low start-up power supply voltage:1.4V(CH4),2.Wide supply voltage range from 1.8v to 7v(CH1CH4),3.High speed operation is possible:Maximum 1MHz,4.Supports for up,flyback and up/down SEPIC converter(CH1CH4),5.Totem-pole type output for MOSFET,6.Built-in On/Off,7.Built-in Short-Circuit Protection.,AT1382B Features:,1.Low start-up power supply voltage:1.4V(CH4),2.Wide supply voltage range from 1.8v to 7v(CH1CH4),3.High speed operation is possible:Maximum 1MHz,4.Supports for up,flyback and up/down SEPIC converter(CH2CH4),5.Totem-pole type output for MOSFET,6.Built-in On/Off,7.Built-in Short-Circuit Protection.,8.Supports for down and up/down zeta conversion(CH1),參考線路,:,線路應用注意事項:,1.如何減少輸出的OverShoot,2.電池偵測注意事項,AT1382A Block Diagram:,AT1382B Block Diagram:,功能概述:,1.電源轉換功能:,a.參考電壓模塊(Reference voltage):,提供IC內部的參考電壓及供給外部電路之參考電壓(typical 0.9v&Max supply current 1mA).,b.三角波震盪模塊(Triangular oscillator):,三角波產生器主要的頻率乃由C,T,與R,T,駔程產生,C,T,:0.3v0.7v;,C,T1,:0.2v0.65v且與C,T,同相;,C,T2,:0.2v0.65v且與C,T,反相.,c.迴授放大比較器(Error amplifier):,迴授比較器乃是比較等比例的輸出電壓與迴授參考電壓(FB),用以控制PWM比較器的輸出狀態,d.PWM比較器模塊:,PWM1比較器是一個電壓對相位的轉換器而產生脈寬調變之控制.PWM比較器主要的輸入:,迴授比較輸出,DTC,Soft-start,SCP,OSC.等.,e.輸出電壓模塊:,輸出模塊為Totem pole結構,用以控制外部的MOSFET之驅動器,f.低電池偵測模塊:,IC 內部提供一個定壓比較器,以利電池電壓比較之用,g.類比放大模塊:,IC 內部提供一個電壓放大器,放大倍率為100倍,以供系統電路應用之用.,輸出控制功能:,2.保護功能:,a:短路保護模塊:,IC 內部每一組輸出都會有,一個短路偵測模塊,其主要的,功能是防止輸出瞬間短 路時,作為保護IC裝置.,b.低電壓保護模塊:,當輸入電壓未達到輸入的額定,電壓時,為防止IC輸出誤動作故,限制其輸出電壓值 為一定值,3.Soft_Start 設定:,輸出CH1CH4的Soft-start 完全一樣,但也都可以被CS所控制,4.輸出電壓制設定:,5.DEAD Time 設定:,6.低電池偵測的線路及偵測電壓的計算:,7.同步整流參考資料:,AT1386/87/88 DC/DC Converter,AT1386 Features:,Low start-up power supply voltage:1.4V(CH6),Wide supply voltage range 2.5V to 7V(CH16),High speed operation is possible:Maximum 1MHz,Supports for up,flyback and up/down SEPIC conversion(CH16),Synchronized rectification on CH1,CH2,Totem-pole type output for MOSFET,Built-in On/Off function,Built-in Soft-Start function,Built-in Short-Circuit Protection.,AT1387 Features:,Low start-up power supply voltage:1.4V(CH6),Wide supply voltage range 2.5V to 7V(CH16),High speed operation is possible:Maximum 1MHz,Supports for up,flyback,and up/down SEPIC conversion(CH3,4,5,6),Synchronized rectification on CH1,CH2,Totem-pole type output for MOSFET,Built-in On/Off function,Built-in Soft-Start function,Built-in Short-Circuit Protection.,Support for down and up Zeta conversion(CH1,2),AT1388 Features:,Low start-up power supply voltage:1.4V(CH6),Wide supply voltage range 2.5V to 7V(CH16),High speed operation is possible:Maximum 1MHz,Supports for up,flyback,and up/down SEPIC conversion(CH2,3,4,5,6),Synchronized rectification on CH1,CH2,Totem-pole type output for MOSFET,Built-in On/Off function,Built-in Soft-Start function,Built-in Short-Circuit Protection.,Support for down and up Zeta conversion(CH1),AT1386 Block Diagram:,AT1387 Block Diagram:,AT1388 Block Diagram:,參考線路,:,當系統關閉時為防止,電池耗電所建議之線路,Example:,可節省電池經由電,阻放電,等到需要時,再啟動,防止系統沒啟動時,電池電壓直接灌電,流至負載,參數設定與計算式:,1.Soft-Start 設定:,2.輸出電壓設定:,3.短路保護時間設定:,4.Dead Time控制準位設定:,AT1457Charge Management IC,Features:,Ideal for Single-Cell(4.1V or 4.2V)and Li-Ion or Li-Pol Packs.,Better Than,+,1%Voltage Regulation Accuracy With Preset Voltages.,Optional Cell-Temperature Monitoring Before and During Charge.,Integrated Voltage and Current Regulation With Programmable Charge-Current and High or Low-Side current Sensing.,Charge Status Output for Single or Dual Led or Host Processor Interface.,Automatic Battery-Recharge feature.,Charge Termination by Minimum Current.,Automatic Low-Power Sleep Mode When VCC is Removed.,Requires Small Number of External Components.,Packaging:8-Pin MSOP.,參考線路:,Power supply voltage,4.5V7V,VBAT=4.1v3v for AT1457,4.2v3.1v for AT1457A,Temperature threshold voltage:,Low:30%,+,3Vcc,High:60,+,3Vcc,4.1v or 4.2V(for A type),3.0v or 3.1v(for A type),AT1457 只支持1 cell鋰電,因為的電壓範圍為4.23V,而AT1457輸入電壓範圍4.57v所以使用2cell鋰電則至少需要8.4v以上的輸入電壓,V,RCH,:Vo,(REG),(output voltage)100mv,+,2mv,如何計算 TS Pin 分壓電組:,AT1741/AT1743 2-CH PWM Controller,AT1741 Features:,High-accuracy reference voltage circuit,(,+,2%).,Built-in short-circuit protection circuit.,Built-in Under voltage Lockout Protection.,Internal 2.5v Reference supply.,Variable Dead time provides control over total Range.,AT1743 Features:,High-accuracy reference voltage circuit,(,+,1%),.,Built-in short-circuit protection circuit.,Built-in Under voltage Lockout Protection.,Internal 2.5v Reference supply.,Variable Dead time provides control over total Range.,AT1741/43輸入電壓範圍3.6v28v,因為output pin 為open collect 故需外加Totem-pole線路,Soft-start Capacitor,輸入電壓為:+12v,ON/OFF控制pin:(on:3V off:0V)or(on:5V off:0v),亮度調節器:03V or 05V,Soft-Start Function,Soft-Start Function,羅亞自激式共振型DC-DC 變壓器,同步整流線路,羅亞自激式共振型波形示意圖:,亞羅式電路頻率計算:,亞羅自激共振電路的震盪頻率 f 是取決於變壓器一次線圈的電感量 L,及電容器 C的容,量大小所得到的共振頻率 如下:,AT1780 Current-Mode PWM Controller,Features:,1.8A,0.21Ohm,14V Power MOSFET,Operating input voltage:2.6V to 12V,Adjustable Output from Vin to 14V,640KHz/1.2MHz pin Selectable switching Frequency,0.1uA shutdown Current.,Built-in soft-start function.,Small 8-pin MOSP Package,三倍 倍壓電路,抑制穩壓,負兩倍 倍壓電路,倍壓線路分析:,假設所有的二極體為理想,使用倍壓線路一般僅適用於低能量輸出,因為此電路是利用電容能量轉移所產,生,故輸出負載功耗大小取決於線路上的電容荷能.,迴路補償線路(Loop compensation):,因IC內部電壓回受迴路為了防止過度的輸出,ripple,不佳的效率 及系統的不穩定,所需外部補償,電路.AT1780的外部補償線路如又圖所示,Rcomp,Ccomp 和 Ccomp2 關係式如下:,