R8CB05BO 10-PIN Green-Mode PFC/PWM Combo CONTROLLER

Transcription

1 GENERAL DESCRIPTION The R8CB05BO is the GreenMoe PFC/PWM Combo controller for Desktop PC an High Density AC Aapter For the power supply, it s input current shaping PFC performance coul be very close to the performance of the CM6800 or ML4800 leaing ege moulation average current topology R8CB05BO offers the use of smaller, lower cost bulk capacitors, reuces power line loaing an stress on the switching FETs, an results in a power supply fully compliant to IEC specifications The R8CB05BO inclues circuits for the implementation of a leaing ege moulation, input current shaping technique boost type PFC an a trailing ege moulation current, PWM The R8CB05BO s PFC an PWM operate at the same frequency, 100kHz A PFC OVP comparator shuts own the PFC section in the event of a suen ecrease in loa The PFC section also inclues peak current limiting for enhance system reliability PFC has a PFCOFFB pin which can use for AC brown out application an etermine the GMth to turn off PFC FEATURES 10Pin SOIC package Use RAC aroun 4~8 Mega Ohm at IAC pin Easy to configure into Boost Follower Enable lowest BOM for power supply with PFC Internally synchronize PFC an PWM in one IC Patente slew rate enhance voltage error amplifier with avance input current shaping technique Universal Line Input Voltage CCM boost or DCM boost with leaing ege moulation PFC using Input Current Shaping Technique Fee forwar IAC pin to o the automatic slope compensation PFCOVP, Precision 1V PFC ILIMIT, PFC TriFault Detect comparator to meet UL1950 Low supply currents; startup: 100uA typical, operating current: 2mA typical Synchronize leaing PFC an trailing ege moulation PWM to reuce ripple current in the storage capacitor between the PFC an PWM sections an to reuce switching noise in the system VINOK Comparator to guarantee to enable PWM when PFC reach steay state High efficiency trailingege current moe PWM Exact 50% PWM maximum uty cycle UVLO, REFOK, an brownout protection Digital PFC an PWM soft start, ~10mS Precision PWM 15V current limit for current moe operation PFCOFFB pin to sense light loa to turn off PFC or PFCOFFB pin to sense Input voltage as AC Brown Out 2007/12/18 Rev 10 Champion Microelectronic Corporation Page 1

2 APPLICATIONS PIN CONFIGURATION Desktop PC AC Aaptor Open Frame 10 Pin SSOP (R10) Top View PIN DESCRIPTION Pin No Symbol Description 1 GND Groun 2 IAC Feeforwar input to o slope compensation an to start up the system During the start up, IAC is connecte to until is greater than 13V Operating Voltage Min Typ Max Unit 0 1 ma 3 I SENSE Current sense input to the PFC current limit comparator 5 07 V 4 VEAO PFC transconuctance voltage error amplifier output 0 6 V 5 V FB PFC transconuctance voltage error amplifier input V 6 V I PWM fee back an current limit comparator input 0 15 V 7 PFCOFFB PFCOFFB; it can turn off PFC stage when it is below 5V 0 V 8 Positive supply V 9 PFC OUT PFC river output 0 V 10 PWM OUT PWM river output 0 V ORDERING INFORMATION Part Number Operation Frequency Initial Accuracy (KHz) Temperature Range Package Min Typ Max R8CB05BOGIR Fpwm = Fpfc = 100Khz to Pin SSOP(R10) Note: 1 G : Suffix for Pb Free Prouct 2 Initial Accuracy : T A = /12/18 Rev 10 Champion Microelectronic Corporation Page 2

3 BLOCK DIAGRAM 2 IAC 4 VEAO 40K IAC 8 400K S Q ISENSE 3 100K PFC CMP R R Q UVB SUM VREFDK 9 VFB 5 GMV V To Ramp UVLO PFCOUT 25V FAULT BROKENWIRE 05V PFC OVP PFCCLK PWMCLK PFC CLK PWM CLK fpfc=100khz 275V 25V VFB VINOK S Q 225V 11V R1 R2 Q UVB VREFDK 10 PFC ILIMIT PWMOUT 1V PFCOFFB 7 SHUTDOWN PFC 10mS 55V 5V GND PWMCLK SOFT START SS 15V PWM CMP PROTECTED BY PATENT 1 GND 6 VI ABSOLUTE MAXIMUM RATINGS Absolute Maximum ratings are those values beyon which the evice coul be permanently amage Parameter Min Max Units V CC MAX 20 V IAC (before start up) GND03 03 V IAC (after start up) GND03 10 V I SENSE Voltage 5 07 V PFC OUT GND V PWM OUT GND V VEAO 0 63 V PFCOFFB GND V Voltage on Any Other Pin GND03 03 V I CC Current (Average) 40 ma Peak PFC OUT Current, Source or Sink 05 A Peak PWM OUT Current, Source or Sink 05 A PFC OUT, PWM OUT Energy Per Cycle 15 μj Junction Temperature 150 Storage Temperature Range Operating Temperature Range Lea Temperature (Solering, 10 sec) 260 Thermal Resistance (θ JA ) 80 /W 2007/12/18 Rev 10 Champion Microelectronic Corporation Page 3

4 ELECTRICAL CHARACTERISTICS Unless otherwise state, these specifications apply Vcc=14V, T A =Operating Temperature Range (Note 1) Symbol Parameter Test Conitions Voltage Error Amplifier (GM v ) R8CB05BO Min Typ Max Unit Input Voltage Range 0 5 V Transconuctance V NONINV = V INV, VEAO = 375V μmho Feeback Reference Voltage V Input Bias Current Note μa Output High Voltage V Output Low Voltage V Sink Current V FB = 3V, VEAO = 6V μa Source Current V FB = 15V, VEAO = 15V μa Open Loop Gain B Power Supply Rejection Ratio 11V < V CC < 165V B IAC Input Impeance (R8CB05BO) ISENSE = 0V, T A =25 35K 40K 50K Ohm PFC OVP Comparator Threshol Voltage V Hysteresis mv PFC I LIMIT Comparator Threshol Voltage V Delay to Output ns V IN OK Comparator Threshol Voltage (R8CB05BO) V Hysteresis V PWM Digital Soft Start Digital Soft Start Timer (Note 2) Right After Start Up 10 ms V I Comparator Threshol Voltage Normal operation without soft start V Delay to Output (Note 2) ns Threshol Voltage During soft start conition mv PFC Trifault Fault Detect HIGH V Time to Fault Detect HIGH V FB =V FAULT DETECT LOW to V FB = OPEN, 470pF from V FB to GND 2 4 ms Fault Detect LOW V 2007/12/18 Rev 10 Champion Microelectronic Corporation Page 4

5 ELECTRICAL CHARACTERISTICS Unless otherwise state, these specifications apply Vcc=14V, T A =Operating Temperature Range (Note 1) Symbol Parameter Test Conitions R8CB05BO Min Typ Max Unit PFCOFFB PFCOFFB Threshol Low PFCOFFB V PFCOFFB Hysteresis mv PFC Frequency Voltage Stability 10V < V CC < 15V 1 % Temperature Stability 2 % Total Variation Line, Temp (R8CB05BO) khz PFC Dea Time (Note 2) us PFC Minimum Duty Cycle I AC =100uA,V FB =255V, I SENSE = 0V 1 % Maximum Duty Cycle I AC =0uA,V FB =20V, I SENSE = 0V % Output Low Rson ohm Output Low Voltage I OUT = 100mA V I OUT = 10mA, V CC = 8V V Output High Rson ohm Output High Voltage I OUT = 100mA, V CC = 15V V Rise/Fall Time (Note 2) C L = 1000pF 50 ns PWM Duty Cycle Range IC % Output Low Rson At room temp ohm Output Low Voltage I OUT = 100mA V I OUT = 10mA, V CC = 8V V Output High Rson (Note 2) At room temp ohm Output High Voltage I OUT = 100mA, V CC = 15V V Rise/Fall Time (Note 2) C L = 1000pF 50 ns Supply StartUp Current V CC = 11V, C L = ua Operating Current V CC = 15V, C L = ma Unervoltage Lockout Threshol V Unervoltage Lockout Hysteresis V Note 1: Limits are guarantee by 100% testing, sampling, or correlation with worstcase test conitions Note 2: Guarantee by esign, not 100% prouction test 2007/12/18 Rev 10 Champion Microelectronic Corporation Page 5

6 TYPICAL PERFORMANCE CHARACTERISTIC Transconuctance (umho) VFB (V) Voltage Error Amplifier (GMv) Transconuctance 2007/12/18 Rev 10 Champion Microelectronic Corporation Page 6

7 Functional Description The R8CB05BO consists of an ICST (Input Current Shaping Technique), CCM (Continuous Conuction Moe) or DCM (Discontinuous Conuction Moe) boost PFC (Power Factor Correction) front en an a synchronize PWM (Pulse With Moulator) back en The R8CB05BO is esigne to replace FAN4803 (8 pin SOP package), which is the secon generation of the ML4803 with 8 pin package It is istinguishe from earlier combo controllers by its low count, innovative input current shaping technique, an very low startup an operating currents The PWM section is eicate to peak current moe operation It uses conventional trailingege moulation, while the PFC uses leaingege moulation This patente Leaing Ege/Trailing Ege (LETE) moulation technique helps to minimize ripple current in the PFC DC bus capacitor The main improvements from ML4803 are: 1 A Green Moe Functions for both PFC an PWM 2 Remove the one pin error amplifier an a back the slew rate enhancement GMv, which is using voltage input instea of current input This transconuctance amplifier will increase the transient response 5 to 10 times from the conventional OP 3 VFB PFC OVP comparator 4 PFC TriFault Detect for UL1950 compliance an enhance safety 5 A fee forwar signal from IAC pin is ae to o the automatic slope compensation This increases the signal to noise ratio uring the light loa; therefore, THD is improve at light loa an high input line voltage 6 R8CB05BO oes not require the blee resistor an it uses the more than 800k ohm resistor between IAC pin an rectifie line voltage to fee the initial current before the chip wakes up 7 VINOK comparator is ae to guarantee PWM cannot turn on until VFB reaches 25V in which PFC boost output is about steay state, typical 380V 8 A 10mS igital PWM soft start circuit is ae 9 10 pin SOP package 10 No internal Zener an OVP comparator The R8CB05BO operates both PFC an PWM sections at 100kHz This allows the use of smaller PWM magnetic an output filter components, while minimizing switching losses in the PFC stage Detaile Pin Descriptions IAC (Pin 2) Typically, it has a feeforwar resistor, RAC, 4Mega~10Mega ohm resistor connecte between this pin an rectifie line input voltage The current of RAC will program the automatic slope compensation for the system This feeforwar signal can increase the signal to noise ratio for the light loa conition or the high input line voltage conition ISENSE (Pin 3) This pin ties to a resistor which senses the PFC input current This signal shoul be negative with respect to the IC groun It internally fees the pulsebypulse current limit comparator an the current sense feeback signal The ILIMIT trip level is 1V The ISENSE feeback is internally multiplie by a gain of four an compare against the internal programme ramp to set the PFC uty cycle The intersection of the boost inuctor current ownslope with the internal programming ramp etermines the boost offtime It requires a RC filter between ISENSE an PFC boost sensing resistor VEAO (Pin 4) This is the PFC slew rate enhance transconuctance amplifier output which nees to connecte with a compensation network Groun VFB (Pin 5) Besies this is the PFC slew rate enhance transconuctance input, it also tie to a couple of protection comparators, PFCOVP, an PFC TriFault Detect V I (Pin 6) This pin is tie to the primary sie PWM current sense resistor or transformer It provies the internal pulsebypulse current limit for the PWM stage (which occurs at 15V) an the peak current moe feeback path for the current moe control of the PWM stage Besies current information, the photocouple also goes into V I pin Therefore, it is the SUM Amplifier input Soft Start is aroun 10mS after the startup( is greater than 13V) Several protection features have been built into the R8CB05BO These inclue softstart, reunant PFC overvoltage protection, PFC TriFault Detect, VINOK, peak current limiting, uty cycle limiting, unervoltage lockout, reference ok comparator an PFCOFFB 2007/12/18 Rev 10 Champion Microelectronic Corporation Page 7

8 PFCOFFB (Pin 7) When this pin is below 5V, PFC gate rive, PFCOUT will be turne off until PFCOFFB pin is greater than 55V When PFCOFFB is below 5V, Veao also been pulle low as well PFCOFFB usually is use for AC Brown Out For AC Brown out, PFCOFFB can be use to sense the brige input voltage When PFCOFFB is below 5V, PFC can be turne off (Pin 8) is the power input connection to the IC The startup current is 100uA The noloa ICC current is 2mA quiescent current will inclue both the IC biasing currents an the PFC an PWM output currents Given the operating frequency an the MOSFET gate charge (Qg), average PFC an PWM output currents can be calculate as IOUT = Qg x F The average magnetizing current require for any gate rive transformers must also be inclue The pin is also assume to be proportional to the PFC output voltage also ties internally to the UVLO circuitry an VREFOK comparator, enabling the IC at 13V an isabling it at 10V must be bypasse with a high quality ceramic bypass capacitor place as close as possible to the IC Goo bypassing is critical to the proper operation of the R8CB05BO is typically prouce by an aitional wining off the boost inuctor or PFC Choke, proviing a voltage that is proportional to the PFC output voltage An external clamp, such as shown in Figure 1, is esirable an propose to limit over voltage to an acceptable value GND 1N5248 Figure 1 Optional Clamp PFCOUT (Pin 9) an PWM OUT (Pin 10) PFC OUT an PWM OUT are the highcurrent power river capable of irectly riving the gate of a power MOSFET with peak currents up to 1A an 05A Both outputs are actively hel low when is below the UVLO threshol level which is 15V or VREFOK comparator is low Power Factor Correction Power factor correction makes a nonlinear loa look like a resistive loa to the AC line For a resistor, the current rawn from the line is in phase with an proportional to the line voltage, so the power factor is unity (one) A common class of nonlinear loa is the input of most power supplies, which use a brige rectifier an capacitive input filter fe from the line The peakcharging effect, which occurs on the input filter capacitor in these supplies, causes brief highamplitue pulses of current to flow from the power line, rather than a sinusoial current in phase with the line voltage Such supplies present a power factor to the line of less than one (ie they cause significant current harmonics of the power line frequency to appear at their input) If the input current rawn by such a supply (or any other nonlinear loa) can be mae to follow the input voltage in instantaneous amplitue, it will appear resistive to the AC line an a unity power factor will be achieve To hol the input current raw of a evice rawing power from the AC line in phase with an proportional to the input voltage, a way must be foun to prevent that evice from loaing the line except in proportion to the instantaneous line voltage The PFC section of the R8CB05BO uses a boostmoe DCDC converter to accomplish this The input to the converter is the full wave rectifie AC line voltage No bulk filtering is applie following the brige rectifier, so the input voltage to the boost converter ranges (at twice line frequency) from zero volts to the peak value of the AC input an back to zero By forcing the boost converter to meet two simultaneous conitions, it is possible to ensure that the current raws from the power line matches the instantaneous line voltage One of these conitions is that the output voltage of the boost converter must be set higher than the peak value of the line voltage A commonly use value is 385VFB, to allow for a high line of 270VAC rms The other conition is that the current that the converter is allowe to raw from the line at any given instant must be proportional to the line voltage This limits the maximum that can be applie about 18V to avoi OVP which allowing to the maximum rating An RC filter at is require between boost trap wining an 2007/12/18 Rev 10 Champion Microelectronic Corporation Page 8

9 PFC Control: Leaing Ege Moulation with Input Current Shaping Technique (ICST) The only ifferences between the conventional PFC control topology an ICST is: the current loop of the conventional control metho is a close loop metho an it requires a etail unerstaning about the system loop gain to esign With ICST, since the current loop is an open loop, it is very straightforwar to implement it The en result of the any PFC system, the power supply is like a pure resistor at low frequency Therefore, current is in phase with voltage In the conventional control, it forces the input current to follow the input voltage In R8CB05BO, the chip thinks if a boost converter nees to behave like a low frequency resistor, what the uty cycle shoul be The following equations is R8CB05BO try to achieve: V R in e = (1) Iin I l = I in (2) Equation 2 means: average boost inuctor current equals to input current V in I l Vout I (3) Therefore, input instantaneous power is about to equal to the output instantaneous power For steay state an for the each phase angle, boost converter DC equation at continuous conuction moe is: V out V in 1 (1 ) = (4) Therefore, equation (6) becomes: I I toff ' = = I I (1 ) T = (7) sw Combine equation (7) an equation (5), an we get: I I I = ( = ' 2 ' ) ' V = R V out e out t T V off R sw e out R e From this simple equation (8), we implement the PFC control section of the R8CB05BO Leaing/Trailing Moulation Conventional Pulse With Moulation (PWM) techniques employ trailing ege moulation in which the switch will turn ON right after the trailing ege of the system clock The error amplifier output is then compare with the moulating ramp When the moulating ramp reaches the level of the error amplifier output voltage, the switch will be turne OFF When the switch is ON, the inuctor current will ramp up The effective uty cycle of the trailing ege moulation is etermine uring the ON time of the switch Figure 2 shows a typical trailing ege control scheme In case of leaing ege moulation, the switch is turne OFF right at the leaing ege of the system clock When the moulating ramp reaches the level of the error amplifier output voltage, the switch will be turne ON The effective utycycle of the leaing ege moulation is etermine uring OFF time of the switch Figure 3 shows a leaing ege control scheme (8) Rearrange above equations, (1), (2),(3), an (4) in term of Vout an, boost converter uty cycle an we can get average boost ioe current equation (5): I (1 ) = 2 V out R e (5) Also, the average ioe current can be expresse as: I 1 T off = I t t T ( ) 0 (6) sw If the value of the boost inuctor is large enough, we can assume I ( t) ~ I It means uring each cycle or we can say uring the sampling, the ioe current is a constant 2007/12/18 Rev 10 Champion Microelectronic Corporation Page 9

10 One of the avantages of this control technique is that it require only one system clock Switch 1(SW1) turns OFF an switch 2 (SW2) turns ON at the same instant to minimize the momentary noloa perio, thus lowering ripple voltage generate by the switching action With such synchronize switching, the ripple voltage of the first stage is reuce Calculation an evaluation have shown that the 120Hz component of the PFC s output ripple voltage can be reuce by as much as 30% using this metho, substantially reucing issipation in the highvoltage PFC capacitor Typical Applications PFC Section: PFC Voltage Loop Error Amp, VEAO The ML4803 utilizes an one pin voltage error amplifier in the PFC section (VEAO) In the R8CB05BO, it is using the slew rate enhance transconuctance amplifier, which is the same as error amplifier in the CM6800 The unique transconuctance profile can spee up the conventional transient response by 10 times The internal reference of the VEAO is 25V The input of the VEAO is VFB pin PFC Voltage Loop Compensation The voltageloop banwith must be set to less than 120Hz to limit the amount of line current harmonic istortion A typical crossover frequency is 30Hz The Voltage Loop Gain (S) ΔV = ΔV V OUT EAO 2 OUTDC ΔVFB ΔV * * ΔVOUT ΔV PIN *25V * ΔVEAO *S*C EAO FB DC *GM V * Z CV Z CV : Compensation Net Work for the Voltage Loop GMv: Transconuctance of VEAO P IN : Average PFC Input Power V OUTDC : PFC Boost Output Voltage; typical esigne value is 380V C DC : PFC Boost Output Capacitor ΔV EAO : This is the necessary change of the VEAO to eliver the esigne average input power The average value is 6V3V=3V since when the input line voltage increases, the elta VEAO will be reuce to eliver the same to the output To over compensate, we choose the elta VEAO is 3V Internal Voltage Ramp The internal ramp current source is programme by way of VEAO pin voltage When VEAO increases the ramp current source is also increase This current source is use to evelop the internal ramp by charging the internal 30pF 12/ 10% capacitor The frequency of the internal programming ramp is set internally to 100kHz Design PFC ISENSE Filtering ISENSE Filter, the RC filter between Rs an ISENSE: There are 2 purposes to a a filter at ISENSE pin: 1) Protection: During start up or inrush current conitions, it will have a large voltage cross Rs, which is the sensing resistor of the PFC boost converter It requires the ISENSE Filter to attenuate the energy 2) Reuce L, the Boost Inuctor: The ISENSE Filter also can reuce the Boost Inuctor value since the ISENSE Filter behaves like an integrator before going ISENSE which is the input of the current error amplifier, IEAO 2007/12/18 Rev 10 Champion Microelectronic Corporation Page 10

11 The I SENSE Filter is a RC filter The resistor value of the I SENSE Filter is between 100 ohm an 50 ohm By selecting R FILTER equal to 50 ohm will keep the offset of the IEAO less than 5mV Usually, we esign the pole of I SENSE Filter at fpfc/6, one sixth of the PFC switching frequency Therefore, the boost inuctor can be reuce 6 times without isturbing the stability Therefore, the capacitor of the I SENSE Filter, C FILTER, will be aroun 283nF IAC, R AC, Automatic Slope Compensation, DCM at high line an light loa, an Startup current There are 4 purposes for IAC pin: 1) For the leaing ege moulation, when the uty cycle is less than 50%, it requires the similar slope compensation, as the uty cycle of the trailing ege moulation is greater than 50% In the R8CB05BO, it is a relatively easy thing to esign Use an more than 800K ohm resistor, R AC to connect IAC pin an the rectifie line voltage It will o the automatic slope compensation If the input boost inuctor is too small, the R AC may nee to be reuce more 2) During the startup perio, Rac also provies the initial startup current, 100uA;therefore, the blee resistor is not neee 3) Since IAC pin with R AC behaves as a feeforwar signal, it also enhances the signal to noise ratio an the THD of the input current 4) It also will try to keep the maximum input power to be constant However, the maximum input power will still go up when the input line voltage goes up Start Up of the system, UVLO, VREFOK an Soft Start During the Startup perio, R AC resistor will provie the start up current~100ua from the rectifie line voltage to IAC pin During the Start up, the soft start function is triggere an the uration of the soft start will last aroun 10mS PFC section wakes up after Start up perio After Start up perio, PFC section will softly start since VEAO is zero before the startup perio Since VEAO is a slew rate enhance transconuctance amplifier (see figure 3), VEAO has a high impeance output like a current source an it will slowly charge the compensation net work which nees to be esigne by using the voltage loop gain equation Before PFC boost output reaches its esign voltage, it is aroun 380V an VFB reaches 25V, PWM section is off PWM section wakes up after PFC reaches steay state PWM section is off all the time before PFC VFB reaches 225V Then internal 10mS igital PWM soft start circuit slowly ramps up the softstart voltage PFC OVP Comparator PFC OVP Comparator sense VFB pin which is the same the voltage loop input The goo thing is the compensation network is connecte to VEAO The PFC OVP function is a relative fast OVP It is not like the conventional error amplifier which is an operational amplifier an it requires a local feeback an it make the OVP action becomes very slow The threshol of the PFC OVP is 25V10% =275V with 250mV hysteresis PFC TriFault Detect Comparator To improve power supply reliability, reuce system component count, an simplify compliance to UL1950 safety stanars, the R8CB05BO inclues PFC TriFault Detect This feature monitors VFB (Pin 5) for certain PFC fault conitions In case of a feeback path failure, the output of the PFC coul go out of safe operating limits With such a failure, VFB will go outsie of its normal operating area Shoul VFB go too low, too high, or open, PFC TriFault Detect senses the error an terminates the PFC output rive PFC TriFault etect is an entirely internal circuit It requires no external components to serve its protective function over voltage an generate For the R8CB05BO system, if is generate from a source that is proportional to the PFC output voltage The PFC OVP will avoi the over voltage Given that 16V on correspons to 380V on the PFC output, 176V on correspons to an acceptable level of 18V Typically, there is a bootstrap wining off the boost inuctor The isn t built in the OVP function For the maximum rating, an external zener clamp is esirable an propose to limit over voltage It is a necessary to put RC filter between bootstrap wining an For =15V, it is sufficient to rive either a power MOSFET or a IGBT 2007/12/18 Rev 10 Champion Microelectronic Corporation Page 11

12 UVLO The UVLO threshol is 13V proviing 3V hysteresis PFCOUT an PWMOUT Both PFCOUT an PWMOUT are CMOS rivers They both have aaptive antishoot through to reuce the switching loss Its pullup is a 30ohm PMOS river an its pullown is a 15ohm NMOS river It can source 05A an sink 1A if the is above 15V PWM Section After 10mS igital soft start, R8CB05BO s PWM is operating as a typical current moe It requires a seconary feeback, typically, it is configure with CM431, an photo couple Since PWM Section is ifferent from CM6800 family, it nees the emitter of the photo couple to connecte with V I instea of the collector The PWM current information also goes into VI Usually, the PWM current information requires a RC filter before goes into the V I Therefore, VI actually is a summing noe from voltage information which is from photo couple an CM431 an current information which is from one en of PWM sensing resistor an the signal goes through a single pole, RC filter then enter the VI pin This RC filter at VI also serves several functions: 1) It protects IC 2) It provies level shift for voltage information 3) It filters the switching noise from current information At normal operation, the threshol voltage of the V I pin is 15V When the V I is greater than 15V, PWM output river will turn off the PWM Power MOSFET When the Soft Start is triggere, the VI threshol is aroun 150mV Soft Start Can be triggere by the following conitions: 1) During the startup ( is less than 10V) 2) Vfb is below ~ 11V During above 2 conitions, the V I threshol is aroun 150mV until the conitions have been remove After above 2 conitions have been remove, the internal Soft Start D to A will ramp up the voltage from ~150mV to 2V Each Soft Start Ramp can last aroun 10mS Component Reuction Components associate with the VRMS an IEAO pins of a typical PFC controller such as the CM6800 have been eliminate The PFC power limit an banwith oes vary with line voltage 2007/12/18 Rev 10 Champion Microelectronic Corporation Page 12

13 Application Circuit (PC Power) EMI GBU808 L IN5406 FG N 008 2W(s) AC INLET IN uF/400V GND 1N5406 5M K 102pF 15V SR160 R8CB05BO 1 10 GND PWM OUT 2 9 IAC PFC OUT SR Isense SR160 PWM OUT 10 1/2W SR140 1N4148 1M T K ER806 14N50 380VDC 180uF/450V 1K 10K 380VDC 1M 1M 4 7 VEAO PFCOFFB 5 6 VFB VI 95V 104pF 10M 68K 470pF/250V 47uF 1N K 1N pF 330K 474pF 473pF 472pF 13K 470pF ISO1A PWM IS 5V 12V PF 102K 1% ISO1A 817C 380VDC B 20A/100V 12V 1K 09N uF/16V 2200uF/16V 47K 01uF 1000PF PWM OUT 09N PF 30A/60V 2200uF/10V 2200uF/63V GND 5V 392K 1% 475K 1% 1/8W 2200PF TL PWM IS GND 02 2W R8CB05BO Marking Rule Note : " represent BO" 2007/12/18 Rev 10 Champion Microelectronic Corporation Page 13

14 θ R8CB05BO PACKAGE DIMENSION 10 PinSSOP (R10) PIN 1 ID θ ZD B F NUMBERING SCHEME Orering Number: R8CB05BOIR (note1) note1: I : 40 ~125 R: SSOP /12/18 Rev 10 Champion Microelectronic Corporation Page 14

15 IMPORTANT NOTICE Champion Microelectronic Corporation (CMC) reserves the right to make changes to its proucts or to iscontinue any integrate circuit prouct or service without notice, an avises its customers to obtain the latest version of relevant information to verify, before placing orers, that the information being relie on is current A few applications using integrate circuit proucts may involve potential risks of eath, personal injury, or severe property or environmental amage CMC integrate circuit proucts are not esigne, intene, authorize, or warrante to be suitable for use in lifesupport applications, evices or systems or other critical applications Use of CMC proucts in such applications is unerstoo to be fully at the risk of the customer In orer to minimize risks associate with the customer s applications, the customer shoul provie aequate esign an operating safeguars HsinChu Heaquarter Sales & Marketing 5F, No 11, Park Avenue II, ScienceBase Inustrial Park, HsinChu City, Taiwan 7F6, No32, Sec 1, Chenggong R, Nangang District, Taipei City 115, Taiwan ROC T E L : T E L : F A X : F A X : /12/18 Rev 10 Champion Microelectronic Corporation Page 15