高效低成本(77+~82+)针对被动PFC市场的主动PFC的IC ,CM6805(CM6800简化版)

CM6805为CMC公司推出的又一款经典的针对,中低端被动PFC市场的一款极具竞争力的IC,此款IC最大的特点,是秉承了CMC一贯的特色,在保持高效性的前提下,进行了 COST DOWN,对电源的整体成本进行了瘦身.相对于CM6800由16个脚位减少到10个脚位,因此减少周围诸多元器件的使用.

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stonegao

LV.2

2008-09-03 12:02

10-PIN Green-Mode PFC/PWM  Combo CONTROLLER - CM6805A

General Description
   The  CM6805A  is  the  Green-Mode  PFC/PWM  Combo controller for  Desktop PC and High  Density AC Adapter. For  the  power  supply,  itˇs  input  current  shaping  PFC performance could be very close to the performance of the CM6800  or   ML4800  leading  edge  modulation  average current topology.

      CM6805A  offers  the  use   of  smaller,  lower  cost  bulk capacitors, reduces power line loading and stress on the switching  FETs,  and  results  in  a  power  supply  fully compliant  to  IEC1000-3-2  specifications.  The  CM6805A includes circuits for the implementation of a leading edge modulation, input current shaping technique ¨boost〃 type PFC and a trailing edge modulation current, PWM.

     The  CM6805Aˇs  PFC  and  PWM  operate  at  the  same frequency, 100kHz. A PFC  OVP comparator shuts down the PFC section in the event of a sudden decrease in load. The  PFC  section  also  includes  peak  current  limiting  for enhanced system reliability.

         PFC has a PFCOFFB pin which can use for AC brown out application and determine the GMth to turn off PFC.

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Features

10-Pin SOIC package
Use RAC as the Startup resistor which can be > 2000K or higher at IAC pin
It can use the HV bipolar to start up the chip and it helps green mode.
Easy to configure into Boost Follower
Enable lowest BOM for power supply with PFC
Internally synchronized PFC and PWM in one IC
Patented slew rate enhanced voltage error amplifier with advanced input current shaping technique
Universal Line Input Voltage
CCM boost or DCM boost with leading edge modulation

PFC using Input Current Shaping Technique
Feed forward IAC pin to do the automatic slope compensation
PFCOVP, Precision -1V PFC ILIMIT, PFC Tri-Fault Detect comparator to meet UL1950

Low supply currents; start-up: 100uA typical, operating current: 2mA typical.
Synchronized leading PFC and trailing edge modulation PWM to reduce ripple current in the storage capacitor between the PFC and PWM sections and to reduce switching noise in the system
VINOK Comparator to guarantee to enable PWM when

PFC reach steady state
High efficiency trailing-edge current mode PWM
Exact 50% PWM maximum duty cycle
UVLO, REFOK, and brownout protection
Digital PFC and PWM soft start, ~10mS
Precision PWM 1.5V current limit for current mode operation
PFCOFFB pin to sense light load to turn off PFC or PFCOFFB pin to sense Input voltage as AC Brown Out

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Applications

Desktop PC

AC Adaptor

Open Frame

gaofengkgb

LV.5

2008-12-17 09:14

@stonegao

10-PINGreen-ModePFC/PWM ComboCONTROLLER-CM6805A GeneralDescription The CM6805A is the Green-Mode PFC/PWM Combocontrollerfor DesktopPCandHigh DensityACAdapter.For the power supply, itˇs input current shaping PFCperformancecouldbeveryclosetotheperformanceoftheCM6800 or ML4800 leading edge modulation averagecurrenttopology. CM6805A offers the use of smaller, lower cost bulkcapacitors,reducespowerlineloadingandstressontheswitching FETs, and results in a power supply fullycompliant to IEC1000-3-2 specifications. The CM6805Aincludescircuitsfortheimplementationofaleadingedgemodulation,inputcurrentshapingtechnique¨boost〃typePFCandatrailingedgemodulationcurrent,PWM. The CM6805Aˇs PFC and PWM operate at the samefrequency,100kHz.APFC OVPcomparatorshutsdownthePFCsectionintheeventofasuddendecreaseinload.The PFC section also includes peak current limiting forenhancedsystemreliability. PFChasaPFCOFFBpinwhichcanuseforACbrownoutapplicationanddeterminetheGMthtoturnoffPFC.---------------------------------------------------------------------------------------------------------------------------------------------Features10-PinSOICpackageUseRACastheStartupresistorwhichcanbe>2000KorhigheratIACpinItcanusetheHVbipolartostartupthechipandithelpsgreenmode.EasytoconfigureintoBoostFollowerEnablelowestBOMforpowersupplywithPFCInternallysynchronizedPFCandPWMinoneICPatentedslewrateenhancedvoltageerroramplifierwithadvancedinputcurrentshapingtechniqueUniversalLineInputVoltageCCMboostorDCMboostwithleadingedgemodulationPFCusingInputCurrentShapingTechniqueFeedforwardIACpintodotheautomaticslopecompensationPFCOVP,Precision-1VPFCILIMIT,PFCTri-FaultDetectcomparatortomeetUL1950Lowsupplycurrents;start-up:100uAtypical,operatingcurrent:2mAtypical.SynchronizedleadingPFCandtrailingedgemodulationPWMtoreduceripplecurrentinthestoragecapacitorbetweenthePFCandPWMsectionsandtoreduceswitchingnoiseinthesystemVINOKComparatortoguaranteetoenablePWMwhenPFCreachsteadystateHighefficiencytrailing-edgecurrentmodePWMExact50%PWMmaximumdutycycleUVLO,REFOK,andbrownoutprotectionDigitalPFCandPWMsoftstart,~10mSPrecisionPWM1.5VcurrentlimitforcurrentmodeoperationPFCOFFBpintosenselightloadtoturnoffPFCorPFCOFFBpintosenseInputvoltageasACBrownOut---------------------------------------------------------------------------------------------------------------------------------------------ApplicationsDesktopPC ACAdaptor OpenFrame

为什么这么好的东东,没有人顶一下,哈哈