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PFCM Design Guide PFCM Design Guide with Analog PFC IC HP SPM & System Engineering Group FAIRCHILD SEMICONDUCTOR 82-3, Dodang-Dong, Wonmi-ku, Puchon, Kyonggi-Do, KOREA Tel) 82-32-680-1834, Fax) 82...
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PFCM Design Guide Contents 1. System Configurations.......................................................................... 2. Protection Circuits Over Current Protection (OCP).........................
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PFCM Design Guide 1. System Configurations Relay RTH PR Thermistor IN(S) LVIC IN(R) Shunt Resistor NSENSEVAC- Control IC Fig.1 Typical block diagram of PFCM system An inrush-current prevention circuit...
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PFCM Design Guide that of OCP level 1. It doesn’t generate the fault out signal but its response is very fast. It will protect the system from short circuit situation during the propagation delay time...
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PFCM Design Guide 3. Design Example (PFCM DEMO BOARD) A general PFC example is implemented for 5[k W] air-conditioning applications whose input voltage is 187~276[V]. Operating conditions of PFCM demo...
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PFCM Design Guide Inductance & Input Current Ripple where: ΔILp-p : Peak to peak current of PFC inductor VIN : Input AC voltage VOUTDC : DC link Voltage f : Switching frequency L : Inductance of P...
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PFCM Design Guide The following is the block diagram of PFC controller ucc3818. The average current mode control is composed of two types of loops- voltage loop and current loop. The voltage loop cont...
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PFCM Design Guide Control Loop Implementation Current Loop [Step 1] Crossover frequency Theoretical crossover frequency is given by following equation. ⇒= 7.6 k Hz (Eq.3) [Step 2] Fz and Fp decision 3...
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PFCM Design Guide FZ=3.3k Hz FC=6.7k Hz FP=20k Hz Fig.5 Desired current error amplifier response 1log20= [1] (Eq.6) π2 Cf R zi RG [2] log20= (Eq.7) 1log20= [3] (Eq.8) π2 Cf R pi Voltage Loop ⋅⋅⋅ 53800...
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PFCM Design Guide Fig.6 Voltage loop circuit Other Parameters RT, CT: Switching frequency decision 6.0 CR TT RT = 15[kΩ] CT = 1[n F] Fs = 40[k Hz] RMO: (Refer to fig.4) RI 002.0250 sensepeak AC GMMAX ...
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PFCM Design Guide Optocoupler RFF UCC3818 CFF Fig.7 Input AC voltage sensing circuit RAX and RL depend on optocoupler : RMS max_ LINEAR max_ )245.0]([18181818 =×Ω+++ Wk PEAKRL AC max_ Ω=LR ][390 RC1 ,...
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PFCM Design Guide Over Current Protection VREF(7.5V) PKLIMIT PFCM UCC3818 Fig.8 Over current protection circuit The actual protection level can be slightly different from the calculated value. It depe...
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PFCM Design Guide Over Voltage Protection RZ OVP1 Fig.9 Over voltage protection circuit About demo board, the designed values are: RX = 15 [kΩ], RY = 1.8 [kΩ], RZ = 870 (270+270+330) [kΩ] And the expe...
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PFCM Design Guide DC-link Voltage Control RVL RVD EA- Vref EAOUT Outer RD2 VSIG OP-AMP Fig.10 DC link voltage control circuit The relation between VDC and parameters is: 11115.7 RR VD VD VDVL VL RV ++...
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PFCM Design Guide 4. Experimental Results Fig. 12 shows the overall schematics of implemented PFC converter. Table 2 shows the components that are used for the implemented hardware. Fig. 13 shows the ...
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PFCM Design Guide Table 2. BOM of PFCM demo board. Item Part Reference Quantity 1 C-Ceramic : 101 2012 C10,C13,C26,C30,C35 5 2 C-Ceramic : 102 2012 C17,C18 2 3 C-Ceramic : 104 2012 SC2,SC4,C9,C14,C21,...
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PFCM Design Guide 36 R-Chip : 100kohm, 1/2W, J, 5025 SR7,SR8 2 37 R-Chip : 10Kohm, 1/8W, J, 2012 SR4,R23,R24,R41 4 38 R-Chip : 10ohm, 1/8W, J, 2012 R13 1 39 R-Chip : 10ohm, 1/8W, J, 2012 SR1 1 40 R-Ch...
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PFCM Design Guide VDC (50V/div) IIN (10A/div) Fig. 13. Full load test results (IIN = 15ARMS) Table 3. Power factor and input power measurement. VAC [V] IAC [A] Power [k W] Power Factor [%] Fig.13 220 ...
