FA5612, FA5613 FUJI Power Supply Control IC Power Factor Correction FA5612 / FA5613 Application Note ’11-4 Fuji Electric Co.,Ltd. Electric Co., Ltd. .0.08Fuji AN-049J Rev.1.0 AN-054E Rev.1.2 Apr.-2011 1 http://www.fujielectric.co.jp/products/semiconductor/ FA5612, FA5613 WARNING 1. This Data Book contains the product specifications, characteristics, data, materials, and structures as of Apr. 2011. The contents are subject to change without notice for specification changes or other reasons. When using a product listed in this Data Book, be sure to obtain the latest specifications. 2. All applications described in this Data Book exemplify the use of Fuji’s products for your reference only. No right or license, either express or implied, under any patent, copyright, trade secret or other intellectual property right owned by Fuji Electric Co., Ltd. is (or shall be deemed) granted. Fuji makes no representation or warranty, whether express or implied, relating to the infringement or alleged infringement of other’s intellectual property rights which may arise from the use of the applications described herein. 3. Although Fuji Electric is enhancing product quality and reliability, a small percentage of semiconductor products may become faulty. When using Fuji Electric semiconductor products in your equipment, you are requested to take adequate safety measures to prevent the equipment from causing a physical injury, fire, or other problem if any of the products become faulty. It is recommended to make your design fail-safe, flame retardant, and free of malfunction. 4. The products introduced in this Data Book are intended for use in the following electronic and electrical equipment which has normal reliability requirements. ▪ Computers ·OA equipment ▪ Communications equipment (terminal devices) ▪ Measurement equipment ▪ Machine tools ·Audiovisual equipment ▪ Electrical home appliance ▪ Personal equipment ▪ Industrial robots etc. 5. If you need to use a product in this Data Book for equipment requiring higher reliability than normal, such as for the equipment listed below, it is imperative to contact Fuji Electric to obtain prior approval. When using these products for such equipment, take adequate measures such as a backup system to prevent the equipment from malfunctioning even if a Fuji’s product incorporated in the equipment becomes faulty. ▪ Transportation equipment (mounted on cars and ships) ▪ Trunk communications equipment ▪ Traffic-signal control equipment ▪ Gas leakage detectors with an auto-shut-off feature ▪ Emergency equipment for responding to disasters and anti-burglary devices ▪ Safety devices 6. Do not use products in this Data Book for the equipment requiring strict reliability such as (without limitation) ▪ Space equipment ▪ Aeronautic equipment ▪ Atomic control equipment ▪ Submarine repeater equipment ▪ Medical equipment 7. Copyright © 1995 by Fuji Electric Co., Ltd. All rights reserved. No part of this Data Book may be reproduced in any form or by any means without the express permission of Fuji Electric. 8. If you have any question about any portion in this Data Book, ask Fuji Electric or its sales agents before using the product. Neither Fuji nor its agents shall be liable for any injury caused by any use of the products not in accordance with instructions set forth herein. Electric Co., Ltd. .0.08Fuji AN-049J Rev.1.0 AN-054E Rev.1.2 Apr.-2011 2 http://www.fujielectric.co.jp/products/semiconductor/ FA5612, FA5613 CONTENTS 1. Description .................... 4 2. Features .................... 4 3. Outline .................... 4 4. Types of FA5612/13 .................... 4 5. Block diagram .................... 5 6. Pin assignment .................... 5 7. Ratings and characteristics .................... 6~10 8. Characteristics curves .................... 11~13 9. Outline of circuit operation .................... 14 10. Description of each circuit block .................... 15~19 11. Descriptions of use for each pin .................... 20~26 12. Advice for design .................... 27~29 13. Example of application circuit .................... 30 Note ▪ The contents are subject to change without notice for specification changes or other reasons. ▪ Parts tolerance and characteristics are not defined in all application described in this Date book. When design an actual circuit for a product, you must determine parts tolerance and characteristics for safe and economical operation. Electric Co., Ltd. .0.08Fuji AN-049J Rev.1.0 AN-054E Rev.1.2 Apr.-2011 3 http://www.fujielectric.co.jp/products/semiconductor/ FA5612, FA5613 1. Description FA5612/13 is control IC for power factor correction converter. It realizes low power consumption by using high voltage CMOS process. Thanks to a average current control, a stable operation is obtained, whereby a power factor of 99% or more is easily available. DC output voltage is controlled under a wide range of load from rated to no load. Further, a unique switching frequency diffusion function incorporated simplifies the line filter. 2. Features ▪ Unique switching frequency diffusion function incorporated ▪ Selectable switching frequency : Diffuse or Fix (60 kHz, 65 kHz) ▪ High-precision over current protection : 0.5V ± 5% ▪ No audible noise at startup by dynamic OVP circuit ▪ Low current consumption by high voltage CMOS process Operating : 2mA (typ.) ▪ Enabled to drive power MOSFET directly. Output peak current, source : 1.5A, sink : 1.5A. ▪ Open/short protection at feedback (FB) pin ▪ Under-voltage lockout FA5612 : 9.6V ON / 9V OFF FA5613 : 13V ON / 9V OFF ▪ 8-pin package: SOP-8, DIP-8 3. Outline SOP-8 DIP-8 5 6.5 8 1 4 4.5 Max. 3.4 3.5 Max. 9.4 0.25 ±0.1 2.54 0.5±0.1 0° ～ 15 ° 7.6 2.54×3=7.62 4. Type of FA5612/13 Type FA5612N FA5612P FA5613N Startup Threshold 9.6V (typ.) 9.6V (typ.) 13V (typ.) Package SOP-8 DIP-8 SOP-8 Electric Co., Ltd. .0.08Fuji AN-049J Rev.1.0 AN-054E Rev.1.2 Apr.-2011 4 http://www.fujielectric.co.jp/products/semiconductor/ FA5612, FA5613 5. Block diagram 6. Pin assignment FB 1 8 VCC VCMP 2 7 OUT VDET 3 6 GND IS 4 5 ICMP FA5612N Pin No. Pin symbol 1 FB 2 VCMP Voltage Loop Compensation 3 VDET AC Voltage Input Input terminal for sinusoidal AC input voltage waveform. 4 IS Current Sense Input Input terminal for inductor current signal. 5 ICMP Current Loop Compensation Output of current error amplifier. Phase compensator circuit is connected. *2 6 GND Ground Ground 7 OUT Output Output for driving a power MOSFET. 8 VCC Power Supply Power supply for IC control circuit and output circuit. *1 Function Description Inverting input for voltage error amplifier. Input terminal of converter output voltage. Output of voltage error amplifier. Phase compensator circuit is connected. *2 Voltage Feedback Input *1 connect the capacitor. *2 connect capacitor and the resistor. Electric Co., Ltd. .0.08Fuji AN-049J Rev.1.0 AN-054E Rev.1.2 Apr.-2011 5 http://www.fujielectric.co.jp/products/semiconductor/ FA5612, FA5613 7. Ratings and characteristics The contents are subject to change without notice. When using a product, be sure to obtain the latest specifications. Stress exceeding absolute maximum ratings may malfunction or damage the device. “+” shows sink and “–“ shows source in current prescription. (1) Absolute Maximum Ratings Item Symbol Ratings Unit Total power supply and Zener Current (VCC) *1 Supply Voltage (VCC) Icc > 4.8mA *1 Icc < 4.8mA Output voltage (OUT) *4 Output current (OUT) *1 Output peak current (OUT) *2 input voltage (FB , VDET) Input current (FB , VDET) *3 Input voltage (VCMP) Input current (VCMP) *3 Input voltage (ICMP) Input current (ICMP) *3 Input voltage (IS) Input current (IS) *3 Power dissipation DIP-8 SOP-8 Operating Junction Temperature Storage temperature Icc+Iz Vcc1 Vcc2 Vout Iout Iout_pk Vfb,Vvdet Ifb,Ivdet Vvcmp Ivcmp Vvcmp Iicmp Vis Iis Pd1 Pd2 Tj Tstg 15 - 0.3 to 28 - 0.3 to Self Limiting - 0.3 to VCC + 0.3 - 1500 to 1500 Self Limiting - 0.3 to 5.0 -100 to 100 - 0.3 to 5.0 - 0.5 to 30 - 0.3 to 5.0 - 0.2 to 30 - 5.0 to 1.0 - 300 to 100 800 400 - 30 to +150 - 40 to +150 mA V V V mA mA V μA V mA V mA V μA mW mW °C °C *1 Must not exceed power dissipation. *2 Period exceeding 1500mA must be 100ns or less. *3 When the pin current flows continuously for 100ns or more. *4 The period of 100ns (dead time period) when the voltage of the terminal OUT changes Low⇒High is out of the question. Maximum dissipation curve Package thermal resistor *5 400mW(SOP) 800mW(DIP) θj-a= 312°C/W, θj-c= 72°C /W (SOP-8) 許容損失 Pd (mW) Maximum disspation θj-a= 156°C/W, θj-c= 50°C /W (DIP-8) -40 25 105 150 Ambience temperature 周囲温度 Ta(℃) Ta (°C) *5 JEDEC standard test board Electric Co., Ltd. .0.08Fuji AN-049J Rev.1.0 AN-054E Rev.1.2 Apr.-2011 6 http://www.fujielectric.co.jp/products/semiconductor/ FA5612, FA5613 (2) Recommended Operating Conditions Item Supply Voltage VDET pin input voltage VDET pin peak input voltage IS pin voltage IS pin connection noise filter resistance Ambiance temperature in operation Symbol Vcc Vvdet Vpvdet Vis Risf Ta Min. 10 0 0.54 - 1.0 -40 Item Symbol Resistance Accuracy 4.7kΩ 12kΩ 13kΩ 27kΩ ±5% ±2% ±5% ±5% Frequency setting resistance *2 Frequency diffusion Rg1 65kHz fixed Rg2 60kHz fixed Rg3 Typ. 18 - Max. 26 2.4 2.4 0.5 100 105 Unit V V V V Ω ℃ Temperature characteristics 200ppm/°C 200ppm/°C 200ppm/°C 200ppm/°C *2) For connection in Fig.2, Ro range: 0 to 100Ω VCC 8 Driver OUT 7 Ro Rg 6 GND Fig.1 IS pin-connected filter resistance Fig.2 Frequency setting resistance Electric Co., Ltd. .0.08Fuji AN-049J Rev.1.0 AN-054E Rev.1.2 Apr.-2011 7 http://www.fujielectric.co.jp/products/semiconductor/ FA5612, FA5613 (3) Electrical Characteristics (Unless otherwise specified, Vfb=2.5V, Vvcmp=2.5V, Vvdet=0V, Vis=0V, Vicmp=2.0V, Vcc=18V, Rg=4.7kΩ, Tj=25°C) “+” shows sink and “–“ shows source in current prescription. Voltage amplifier (FB, VCMP pin) Item Voltage feedback input threshold Symbol Vref Condition Ivcmp = 0uA Min. 2.450 Typ. 2.500 Max. 2.550 Unit V Line regulation Regline Vfb = Vref, Vcc = 10V to 26V - 12.5 - 12.5 mV Temperature stability Transconductance VrefdT Gmv Ivsrc Ivsnk Vvcmph Vfb = vref, Tj = - 30°C to 150°C Vfb = Vref ± 0.3V Source : Vfb = 1.5V Sink : Vfb = 3.5V Vfb = 1.5V Source : Vfb = 1.5V - 0.5 70 - 70 30 - 90 - 50 50 - 0.5 120 - 30 70 5.5 mV/°C µmho µA µA V - 170 - 140 - 110 µA VCMP output current VCMP output H voltage VCMP transient response output current VCMP transient response detection voltage Iresp 0.902 *Vref Vresp 0.940 *Vref 0.978 *Vref V Current amplifier (ICMP pin) Item Transconductance Output current ICMP clamp voltage Symbol Gmc Icsrc Icsnk Vclamp Condition Vis= - 0.2V to - 0.4V, Vvdet *1 Source : Vvdet = 3.5V Sink : Vis = -2.0V, Vicmp = 3.0V Iicmp max = 320μA Min. 40 - 70 30 Typ. 60 - 50 50 Max. 80 - 30 70 Unit µmho µA µA 2.6 2.7 2.9 V Condition Vvdet = 0V, Vvdet = 2.4V Vvcmp = 1V, Iicmp = 0μA Vvdet = 0.3V, 1.3V Vis = 0.1V to -0.2V Min. - 1.5 0.3 Typ. -0.5 0.5 Max. 0.5 0.70 Condition Min. *1 Vvdet is for when Vis = -0.3V, Iicmp = 0µA Multiplier Item VDET input bias current VCMP threshold voltage Symbol Ivdet Vthvcmp Output voltage coefficient K 0 0.7 Unit μA V 0.95 - Oscillator Item Symbol Frequency diffusion (reference frequency) Fswref Vvdet = 0.88V, Vis = - 0.18V, Vvcmp *1, Iicmp = 0µA, FswrefdT Vvdet = 0.88V, Vis = - 0.18V, Vvcmp *1, Iicmp = 0µA,Tj=-30°C to 125°C Fswmax Frequency temperature stability Frequency diffusion (maximum frequency) Frequency diffusion, (minimum frequency) Fixed frequency 1 Fixed frequency 2 Maximum duty cycle Typ. Max. Unit 54 60 66 kHz -0.06 - 0.06 kHz/°C Vvcmp = 0V, Vvdet = 2.4V 64 68 70 kHz Fswmin Vvcmp = 0V, Vvdet = 0V 50 52 55 kHz Fsw1 Fsw2 Vout2 < Vout Vout1 < Vout < Vout2 Vvdet = 2.4V, ICMP no connect 54 58.5 60 65 66 71.5 kHz kHz 91 94 97 % DMAX *1 Vvcmp is for when Vvdet = 0.88V, Vis = -0.18V, Iicmp = 0µA Electric Co., Ltd. .0.08Fuji AN-049J Rev.1.0 AN-054E Rev.1.2 Apr.-2011 8 http://www.fujielectric.co.jp/products/semiconductor/ FA5612, FA5613 Overvoltage protection comparator (FB pin) Item Symbol Static OVP threshold voltage Hysteresis Static OVP temperature stability Dynamic OVP threshold voltage ⊿OVP Condition Vfb = 2.5V to 2.9V, Vsovp Vvcmp = 0V, Vvdet = 0V Vfb = 2.9V to 2.5V, Vsovphys Vvcmp = 0V, Vvdet = 0V Vfb = 2.5V to 2.9V, Vvcmp = 0V VsovpdT Vvdet = 0V, Tj= -30°C to 125°C Vfb = 2.5V to 2.8V, Vdovp Vvcmp = 1V, Vvdet = 2V ⊿OVP Vsovpn -Vdovp Min. Typ. Max. Unit 1.070*Vref 1.090*Vref 1.105*Vref V 0.005*Vref 0.020*Vref 0.040*Vref V -0.0001*Vref - 0.0001*Vref V/°C 1.025*Vref 1.050*Vref 1.075*Vref V 50 95 140 mV FB short detection comparator (FB pin) Item Input threshold voltage Symbol Vthfb Pull-down resistance Rfb Condition Vfb = 0V to 1V, Vvcmp = 0V Vfb = 2.5V Min. Typ. Max. Unit 0.1 0.3 0.5 V 2.0 2.5 3.0 MΩ Overcurrent detection comparator (IS pin) Item Symbol Condition Min. Typ. Max. Unit IS offset voltage IS pin voltage Visof Vis_054 Vvdet = -0.25V, Vvcmp = 0.6V Vvdet = 0.54V, Vvcmp = 5.0V Vvdet max = 1.2V, Vvdet min = 0V, Fvdet = 50kHz, Dvdet=50% Vvdet max = 1.8V, Vvdet min = 0V, Fvdet = 50kHz, Dvdet=50% Vvdet max = 1.2V, Vvdet min = 0V, Fvdet = 50kHz Dvdet=50%,Vis = -0.4V to -0.6V Tj=-30°C to 125°C Vvdet max = 1.2V, to 1.8V Vvdet min = 0V, Fvdet = 50kHz Dvdet=50%,Vis= -Vocpl + 0.05V Vvdet max = 1.8V to 1.0V, Vvdet min = 0V, Fvdet = 50kHz Dvdet=50%,Vis= -Vocpl + 0.05V Vvdet max = 1.8V Vvdet min = 0V, Fvdet = 50kHz Dvdet=50%,Vis= -Vocpl + 0.05V Vis= -0.6V Vis = Vocpl + 30mV to-1.0V Pulse signal Vvcmp = 0V, Vis = 0V 0 - 0.43 30 - 0.38 60 - 0.33 mV V - 0.525 - 0.50 - 0.475 V - 0.432 - 0.40 - 0.368 V - 0.1 - 0.1 mV/°C 1.54 1.60 1.66 V 1.30 1.35 1.40 V 0.25 0.30 0.35 V 300 450 600 ns 200 350 500 ns Vocpl IS threshold voltage Vocph IS threshold voltage temperature characteristics VocpldT Vvdeth VDET threshold voltage Vvdetl IS threshold change voltage Vvdets Blanking time *1 Tblk Delay time Tdly Input bias current Iis - 170 - 120 - 70 μA *1 Includes delay time Output (OUT pin) Item Symbol Output voltage (L) Voutl Output voltage (H) Vouth Output rise time Output fall time Tr Tf Condition Vfb = 0V, Vvcmp = 0.3V, Vicmp = 3V to 2V, Sink : Iout = 100mA Vvcmp = 0.3V, Vicmp = 3V to 2V, Source : Iout = - 100mA CL = 1nF CL= 1nF Min. Typ. Max. Unit - 0.5 1.0 V 15.5 16.5 - V - 50 50 - ns ns Electric Co., Ltd. .0.08Fuji AN-049J Rev.1.0 AN-054E Rev.1.2 Apr.-2011 9 http://www.fujielectric.co.jp/products/semiconductor/ FA5612, FA5613 Frequency setting (OUT pin) Item Detection current OUT threshold voltage Frequency setting time *1 Detection time *2 Symbol Istate Vout1 Vout2 Tset Tdet Condition Tj=-30°C to 125°C Tj=-30°C to 125°C Tj=-30°C to 125°C Vvcmp = 0V, Vicmp = 0V Vfb = 2V Vvcmp = 0V, Vicmp = 0V VFfb= 2V Min. 34 260 700 Typ. 40 310 760 Max. 46 390 830 Unit μA mV mV 4.1 5.9 7.7 ms 420 530 640 μs *1: Time elapsing until detection current is outputted from OUT pin after removal of UVLO *2: Period during which detection current is outputted from OUT pin Low voltage protection (VCC pin) Item Symbol ON threshold voltage Vccon OFF threshold voltage Vccoff Hysteresis Vcchys Condition FA5612: Vcc= 8V to 11V FA5613: Vcc= 11V to 15V Vcc= 11V to 7V FA5612 FA5613 Min. 8.6 11.5 8.0 0.4 3.5 Typ. 9.6 13 9.0 0.6 4.0 Max. 10.6 14.5 10.0 0.8 4.5 Unit V V V V V Condition Vcc = 8V, Vvcmp = 0V Vicmp =0V OUT pin no load OUT pin no load Vvcmp=0V Vcc = 18V, Vfb = 0V Vvcmp=0V, Vicmp =0V Min. Typ. Max. Unit 70 90 110 µA - 2.0 4.0 mA - 1.8 3.8 mA 80 110 180 µA All devices (VCC pin) Item Symbol Start-up current Istart Operating current Icc OFF time current Iccoff Standby current Istb Electric Co., Ltd. .0.08Fuji AN-049J Rev.1.0 AN-054E Rev.1.2 Apr.-2011 10 http://www.fujielectric.co.jp/products/semiconductor/ FA5612, FA5613 8. Characteristics curves (Unless otherwise specified, Vfb = 2.5V, Vvcmp = 2.5V, Vvdet = 0V, Vis = 0V, Vicmp = 2.0V, Vcc = 18V, Rg = 4.7kΩ, Tj = 25°C) Voltage error amplifier: Input threshold (Vref) vs. Junction temperature (Tj) 2.55 2.55 2.53 2.53 2.51 2.51 Vref [V] Vref [V] Voltage error amplifier: Input threshold (Vref) vs. Supply voltage (Vcc) 2.49 2.49 2.47 2.47 2.45 2.45 10 15 20 25 -50 30 0 50 Fswref,Fswmax,Fswmin [kHz] Fswref,Fswmax,Fswmin [kHz] 75 70 Fswmax 66 62 Fswref 58 54 Fswmin 50 70 Fswmax 65 60 Fswref 55 Fswmin 50 45 10 15 20 25 30 -50 0 50 Vcc [V] 100 150 Tj [°C] Oscillator: Fixed frequency 1,2 (Fswr1, Fsw2) vs. Junction temperature (Tj) Oscillator: Fixed frequency 1,2 (Fswr1, Fsw2) vs. Supply voltage (Vcc) 75 70 70 66 Fsw2(65kHz) 62 Fsw1(60kHz) 58 Fsw1,Fsw2 [kHz] Fsw1,Fsw2 [kHz] 150 Oscillator: Reference, maximum, minimum frequency (Fswref, Fswmax, Fswmin) vs. Junction temperature (Tj) Oscillator: Reference, maximum, minimum frequency ） (Fswref, Fswmax, Fswmin) vs. Supply voltage (Vcc) 54 Fsw2(65kHz) 65 60 Fsw1(60kHz) 55 50 50 45 10 15 20 25 30 -50 0 50 Vcc [V] 100 150 Tj [°C] Oscillator: Maximum duty cycle (Dmax) vs. Junction temperature (Tj) Overcurrent detection: IS threshold voltage (Vocpl, Vovph) vs. Junction temperature (Tj) 98.0 -0.37 97.0 -0.39 96.0 -0.41 Vocpl,Vocph [V] Dmax [%] 100 Tj [°C] Vcc [V] 95.0 94.0 93.0 92.0 91.0 Vocph -0.43 -0.45 -0.47 Vocpl -0.49 -0.51 90.0 -0.53 -50 0 50 100 150 -50 Tj [°C] 0 50 100 150 Tj [°C] Electric Co., Ltd. .0.08Fuji AN-049J Rev.1.0 AN-054E Rev.1.2 Apr.-2011 11 http://www.fujielectric.co.jp/products/semiconductor/ FA5612, FA5613 Current error amplifier: Output current (Ivcmp) vs. FB pin voltage (Vfb) 60 40 40 20 20 Ivcmp [uA] Iicmp [uA] Current error amplifier: Output current (Iicmp) vs. IS pin voltage (Vis) 60 0 -20 0 -20 -40 -40 -60 -0.6 -60 -0.5 -0.4 -0.3 -0.2 -0.1 1.0 0 1.5 2.0 4.0 1.095 Vdovp / Vref, Vsovp / Vref 0 Vvcmp=0.6V -100 Vis [V] 3.5 1.105 100 Vvcmp=2.0V -200 Vvcmp=1.5V -300 Vvcmp=1.0V -400 Vvcmp=3.0V -500 0.5 1.0 1.5 2.0 2.5 Vsovp 1.085 1.075 1.065 1.055 1.045 Vdovp 1.035 1.025 3.0 -50 0 Vvdet [V] 50 100 150 Tj [°C] OUT pin: Output voltage(H) (Vouth) vs. Supply voltage (Vcc) Vcc - Vouth OUT pin: Output voltage(L) (Voutl) vs. Supply voltage (Vcc) 0.8 2 0.7 1.8 1.6 Vcc - Vouth [V] 0.6 Voutl [V] 3.0 Overvoltage comparator: Dynamic/static OVP (Vdovp/Vref, Vsovp/Vref) vs. Junction temperature (Tj) Multiplier: IS pin voltage (Vis) vs. VDET pin voltage (Vvdet) -600 0.0 2.5 Vfb [V] Vis [V] 0.5 0.4 0.3 0.2 1.4 1.2 1 0.8 0.6 0.4 0.2 0.1 0 0 10 15 20 25 10 30 15 20 25 30 Vcc [V] Vcc [V] Electric Co., Ltd. .0.08Fuji AN-049J Rev.1.0 AN-054E Rev.1.2 Apr.-2011 12 http://www.fujielectric.co.jp/products/semiconductor/ FA5612, FA5613 FA5612 Current consumption: Operating current (Icc) vs. Supply voltage (Vcc) Under voltage lockout: VCC threshold voltage (Vccon, Vccoff) vs. Junction temperature (Tj) FA5612 4.0 3.5 Vccon, Vccoff [V] Icc [mA] 3.0 2.5 2.0 1.5 1.0 10.5 10.3 10.1 9.9 9.7 9.5 9.3 9.1 Vccon 8.9 8.7 8.5 0.5 0.0 0 5 10 15 20 25 30 Vccoff -50 0 Vcc [V] Current consumption: Operating current (Icc) vs. Supply voltage (Vcc) FA5613 4.0 100 150 Under voltage lockout: VCC threshold voltage (Vccon, Vccoff) vs. Junction temperature (Tj) 14.5 3.5 FA5613 13.5 Vccon, Vccoff [V] 3.0 Icc [mA] 50 Tj [°C] 2.5 2.0 1.5 1.0 12.5 Vccon 11.5 10.5 Vccoff 9.5 0.5 0.0 8.5 0 5 10 15 20 25 30 -50 0 Vcc [V] 50 100 150 Tj [°C] Current consumption: Operating current (Icc) vs. Junction temperature (Tj) 4.0 3.5 Icc [mA] 3.0 2.5 2.0 1.5 1.0 0.5 0.0 -50 0 50 100 150 Tj [°C] Overvoltage comparator ⊿OVP ⊿OVP 過電圧コンパレータ vs. Junction temperature (Tj) vs. ジャンクション温度（Tj） 電圧誤差増幅 過渡応答検出電圧（Vresp） Current error amplifier. Output current (Iicmp) vs. Junction temperature (Tj) vs. ジャンクション温度（Tj） 140 130 ⊿OVP [mV] Vresp [V/V] 0.970 0.965 0.960 0.955 0.950 0.945 0.940 120 110 100 0.935 0.930 0.925 90 80 70 60 50 -50 0 50 100 150 -50 Tj [℃] 0 50 100 150 Tj [ ℃] Electric Co., Ltd. .0.08Fuji AN-049J Rev.1.0 AN-054E Rev.1.2 Apr.-2011 13 http://www.fujielectric.co.jp/products/semiconductor/ FA5612, FA5613 9. Outline of circuit operation FA5612/FA5613 are controllers for power factor correction converter using boost topology. These IC are designed for the CCM mode operation with the average current control. The operations, (1) Switching and (2) Power factor collection, are explained as below with the simplified circuit diagram shown in Fig.1. (1) Switching operation Fig. 2 outlines the waveform of each part of switching operation at a steady state. The operation is as follows. I. Set signal of switching frequency outputted from the oscillator sets RS. F/F, whereby OUT pin voltage goes high, thus turning on Q1. ... (t1) II. Q1 turned on raises the current of L1. The current of L1 is converted by Rs connected on GND side into a voltage and is inputted to IS pin (VIS). VIS is compared by current amplifier (CUR. AMP) with reference voltage that is obtained via arithmetic output by multiplier (MUL) from input voltage monitoring VDET and VCMP that is obtained by feedback from output and error amplification. Current amplifier output (ICMP) is compared by PWM comparator (PWM. COMP) with slope waveform outputted from oscillator and, as soon as it attains the reference value, reset signal enters RS. F/F, thereby turning off Q1. ... (t2) III. Q1 turned off inverts the voltage of L1. While a current is being fed to the output via D1, the current of L1 reduces. Set signal outputted from internal oscillator transfers the circuit to the next switching cycle. ... (t1) Fig.1 Block diagram of operating circuit (2) Power factor correcting operation The voltage at VCMP pin that constitutes output of error amplifier (ERR.AMP) is almost DC voltage at a steady state, because of connected phase compensation capacitance. This voltage is inputted to multiplier. Another input to multiplier is a waveform obtained by rectifying AC input voltage. A multiplier multiplies these two of input and outputs a sinusoidal wave proportional to AC input voltage. This outputted sinusoidal voltage waveform is applied as a reference inductor current to current amplifier (CUR.AMP). Therefore, the inductor current's mean value forms a sinusoidal waveform. The current of inductor L1 is deprived of switching ripples by C1 and is turned into a average current. Thus, the current from AC input voltage becomes practically sinusoidal, thus improving the power factor. L1 AC Fig.2 Waveforms of switching operation (outline) D1 I C1 Q1 t Rs t V 4 V 3 (正弦波) Sinusoidal t ICMP 5 IL Detector C1 removes ripples caused CUR.AMP t VDET V IS MUL by switching from current ERR.AMP 1 V (正弦波) Sinusoidal 2 FB t VCMP V (ほぼDC) Almost DC t Fig.4 Power factor corrected waveform Fig.3 Aspects of waveforms at different parts Electric Co., Ltd. .0.08Fuji AN-049J Rev.1.0 AN-054E Rev.1.2 Apr.-2011 14 http://www.fujielectric.co.jp/products/semiconductor/ FA5612, FA5613 10. Description of each circuit block OUT (1) Frequency setting circuit Driver Ro 7 The switching frequency is selectable out of 3 modes by resistance Rg connected between OUT and GND pins. ▪ Mode 1: Frequency diffusion 50 kHz to 70 kHz ▪ Mode 2: Fixed frequency 1 65 kHz ▪ Mode 3: Fixed frequency 2 60 kHz Istate UVLO_L State Set Rg END信号： END signal: 各 ブロック始動開始 Each block starts up OSC The status setting is completed after FB short detection or UVLO are canceled. The switching operation will start after this completion. Therefore, the mode will not change while operating. Fig.5 Frequency setting circuit VCC Vccon As an example, the operation of frequency setting which is in case of a cancellation of UVLO is shown in Fig. 6. IC starts to operate after Vcc exceeds Vccon. Then after 5.9ms, the OUT pin outputs current Istate (40mA (typ.)) during 530us. The current generates a voltage at OUT pin because external resistors (Ro and Rg) are connected to OUT pin. The frequency setting is done with based on this OUT pin voltage. The internal circuits start switching operation after frequency setting. Internal power 内部電源 supply Istate END END信号 signal 0.5V Likewise, in case of cancellation of FB short detection, 5.9ms after the cancellation, a current is outputted from OUT pin for 530us, and then switching starts. VCMP Istate*(Ro+Rg) OUT 0V OUT pin has in its inside reference voltages of 2 levels, or Vout1 (310mV (typ.)) and Vout2 (760mV (typ.)) To select a frequency, a reference voltage is compared with OUT pin voltage while current Istate is flowing. The relationship is as follows. 時間 time Tset Tdet 5.9ms 530us Fig.6 Frequency setting sequence OUT pin voltage Mode Frequency OUT pin < Vout1 Mode1 Frequency diffusion Vout1 < OUT pin < Vout2 Mode2 Fixed frequency 65kHz Vout2 < OUT pin Mode3 Fixed frequency 60kHz (2) Oscillator Oscillator outputs two signals. One is a set signal to flip-flop for setting the OUT pin to Vcc level. Another is a sawtooth signal for PWM comparison. The oscillation frequency is set by frequency setting circuit to either the frequency diffusion mode or 2 kinds of the fixed frequency mode. (2-1) Frequency diffusion When the frequency diffusion mode is selected, the frequency changes between 50 and 70 kHz according to the input/output status of PFC power supply. The optimized frequency diffusion based on input/output status realizes a low noise operation with a wide operation range. OSC block determines the frequency based on VDET pin input voltage and multiplier block output voltage. When the phase angle is range of 0° to 30° or 150° to 180° approximately, the frequency rises in proportion to VDET pin voltage. When it is range of 30° to 150° approximately, the frequency is reversely proportional to the multiplier output. (Fig.8) When the multiplier output is high like when PFC output current is large, the frequency drop is bigger. And it is small in case of reverse situation. VDET 3 CUR.AMP. VCMP 2 Multiplier IL Detector OSC PWM Comp. signal F.F. Set Set信号 Fig.7 Block diagram for oscillator area The approximate frequency (Fsw_b) is given by an equation below when the phase angle is range of 30° to 150°. Fsw_b = 75 – 71.4 × (IS pin voltage) [kHz] Electric Co., Ltd. .0.08Fuji AN-049J Rev.1.0 AN-054E Rev.1.2 Apr.-2011 15 http://www.fujielectric.co.jp/products/semiconductor/ FA5612, FA5613 (2-2) Maximum and minimum frequencies in frequency diffusion mode As stated above, the switching frequency in the frequency diffusion mode depends on VDET pin or multiplier output voltage within maximum and minimum frequencies determined. However, maximum or minimum frequency may never appear under some conditions while 1/2 of AC cycle. Region subject 乗算器出力により to変化する領域 multiplier output Fsw 70kHz VDET電圧により Region subject 変化する領域 to VDET voltage (3) Error amplifier The error amplifier is a circuit for controlling PFC output to a certain level. This IC adopts a transconductance amplifier. The non-inverting input terminal for the error amplifier is connected to the internal reference voltage of 2.5 V (typ.) The inverting input terminal (FB) receives the output voltage, usually resistively divided, from power factor correction converter. For FB open detecting function, this terminal is connected to a pull-down resistor of 2.5MΩ inside the IC. Error amplifier output (VCMP) is connected to multiplier (MUL) to control the inductor current. Output voltage Vout of power factor correction converter usually contains a lot of ripples of double the AC line frequency (50 or 60 Hz). When ripples corresponding to double the AC frequency appear excessively on the error amplifier output, power factor correction converter will not operate stably. So, a capacitor and resistor network is connected between pin 2 (VCMP) which is output of the error amplifier and GND for phase compensation. Increasing the capacitance in the phase compensation network improves the power factor, but the transient responsivity becomes slow. The error amplifier in FA5612/13 has a function of improving the transient responsivity. When the load has suddenly become so heavy, the FB pin voltage drops much. If lowered FB pin voltage is below transient response detection voltage (Vresp), the transient response correction circuit increases output current of error amplifier up to the transient response output current (Iresp). Thus, the VCMP pin voltage rises quickly to increase the output current and suppress the output voltage drop. 50kHz 30° 60° 90° 120° 150° 180° 位相角 Phase angle Fig.8 Oscillation frequency vs. phase angle R3 C4 C5 Vout 2 VCMP VREF(2.5V) R1 FB MUL 1 R2 C3 2.5M Ω ERRAMP Open/Short Ｃｏｍｐ SP Vthfb(0.3V) Ｄｙｎａｍｉｃ ＯＶＰ O.V.P Static ＯＶＰ Fig.9 Error amplifier and overvoltage (4) Overvoltage protection circuit (OVP) This is a circuit for limiting the voltage when the output voltage of power factor correction converter has exceeded the setting. When converter is started up or when the load has suddenly changed, the converter output voltage may rise beyond the setting. In such a case, OVP circuit prevents an over voltage and protects the converter. FA5612/13 has a dynamic OVP function and a static OVP function. The dynamic OVP function restricts the multiplier gain depending on rising of FB pin voltage while FB pin voltage exceeds 2.5 V. The static OVP function makes OUT pulses stop while FB pin voltage exceeds 1.09 time of the reference voltage. In normal operation, the FB pin voltage is 2.5 V that is almost the same as the reference voltage of error amplifier. When the FB pin voltage exceeds 2.5 V by startup or a sudden change of load, the dynamic OVP function reduces output current by lowering the multiplier gain. Then, if the FB pin voltage still rises and exceeds the reference voltage of a static OVP function, FA5612/13 stops the output pulses. OUT pulses stopped by the overvoltage protection are resumed as soon as the output voltage lowers back to 1.07 times the reference voltage. protection circuit Vo 7 OUT SP Output stop 出力停止 0.3V Detect 検出 R1 Open オープン FB 1 R2 2.5MΩ ショート Short VFB=0V Fig.10 FB open/short detector (5) FB short/open detector On the circuit of Fig. 10, if the FB pin voltage is zero because of R2 short or R1 open, the error amplifier can not control the constant voltage. Therefore, the output voltage rises abnormally. In such a case, the overvoltage protection circuit could not operate because the output voltage detection is faulty. Electric Co., Ltd. .0.08Fuji AN-049J Rev.1.0 AN-054E Rev.1.2 Apr.-2011 16 http://www.fujielectric.co.jp/products/semiconductor/ FA5612, FA5613 To avoid such inconvenience, the IC has FB short detector. The circuit consists of reference voltage of 0.3 V (typ.) and comparator (SP). When the FB pin input voltage has dropped below 0.3 V because of R2 short or R1 open, the output of comparator (SP) is inverted to stop the IC output. The PFC converter outputs a voltage corresponding to the input voltage even before startup because of the boost topology. That is why, this function never operate as long as the converter is normal. In case of an open failure of the FB pin FA5612/13 stops the output pulse by this function because a pull-down resistor of 2.5 MΩ inside the IC is connected to the FB pin. If the FB pin voltage has dropped to almost zero, the IC output will stop. When the FB pin voltage returns normal then, OUT pulses will reappear. Sinusoidal Sinusoidal Almost DC (6) Multiplier Multiplier is the circuit for controlling the input current as the sinusoidal wave forms the same as input voltage. An input is connected to VDET pin and is inputted the dividing voltage after being rectified from AC input voltage. The other input is connected to error amplifier output (VCMP). Normally, the error amplifier output is almost DC, and multiplier outputs a sinusoidal waveform voltage whose amplitude changes according to the error amplifier output voltage. The multiplier output constitutes a reference for current comparator to control the input current to a sinusoidal waveform (Fig. 11). Fig.11 Multiplier It usually makes MUL pin peal voltage set to 0.65 to 2.4 V in the all AC input range. The voltage obtained by rectifying the AC input voltage contains many noises attributable to switching by Q1. To eliminate the influence by the noise, filtering capacitance C6 is provided usually. (7) Current detector IL. Detector inverts and amplifies a voltage obtained by voltage-current conversion via current detecting resistance Rs of the inductor current. Current amplifier (CUR. AMP) is error amplifier that composes a current loop to make the input current follow a sinusoidal waveform. Current amplifier receives IL. Detector output and multiplier (MUL) output, subjects them to comparison and error amplification, and outputs the result to PMW comparator (PWM. COMP). Current amplifier is a transconductance amplifier the same as error amplifier. Capacitance and resistance connected between output terminal (ICMP) and GND for phase compensation eliminate switching ripples of the input current. The current detector output is clamped to Vclamp: 2.7 V by clamp circuit that constitutes an upper limit of voltage. Fig.12 Current detector and overcurrent (8) Overcurrent protection circuit (OCP) protection circuit OCP circuit is the circuit to detect the inductor current, and is to stop the output pulse to protect MOSFET when detected current exceeds certain intensity. A detected voltage by sense resistor Rs connected to GND is inputted to the IS pin, is converted by the IL_Detector which is an inverting amplifier, and is compared by overcurrent detection comparator. When IS pin voltage lowers below a threshold value (OCP level), overcurrent protection circuit outputs a signal of an overcurrent status. The signal of overcurrent status resets a flip-flop for the OUT pulse, and then turns MOSFET off. When IS voltage gets near a threshold value, overcurrent protection circuit lowers the gain of multiplier (MUL) to suppress the input current, thereby suppressing the audible noise of inductor attributable to an overcurrent. Electric Co., Ltd. .0.08Fuji AN-049J Rev.1.0 AN-054E Rev.1.2 Apr.-2011 17 http://www.fujielectric.co.jp/products/semiconductor/ FA5612, FA5613 OCP level is changed depending on the peak voltage of VDET pin by VIN_Detector as follows. While period A, OCP level is set to Vocph (-0.4 V) because VDET pin voltage exceeds threshold voltage Vvdeth (1.6 V). OCP level is changed only when VDET pin voltage is below Vvdets (0.3V). At this time, the inductor current is low enough, and therefore will not abruptly change. Further, if the load current is very low such VDET will not be below 0.3 V, the OCP level will not change over regardless of VDET. During period B, VDET will never go below threshold voltage Vvdetl: 1.35 V. Therefore, OCP level will not change either. Some time in period C, VDET will be below threshold voltage Vvdetl: 1.35 V, whereby OCP level is set to Vocpl (-0.5 V). The same as period A, OCP level is changed only when VDET pin voltage is below Vvdets (0.3 V). VDET terminal voltage Period A Period B Period C OCP level Fig.13 Overcurrent protection (OCP) level and VDET voltage (9) Undervoltage lockout circuit (UVLO) FA5612/13 has the UVLO circuit to avoid unexpected operation when the source voltage has dropped. The IC starts operation when the source voltage rising from zero has reached 9.6 V (typ.) for FA5612, or 13 V (typ.) for FA5613. After startup, each of ICs stops operating when the source voltage has dropped to 9 V (typ.) While the IC stops a switching operation by UVLO circuit, the IC keeps OUT pin voltage low and further reduces IC consumption current to below 100 μA. (10) Output circuit The output circuit consists of a push-pull circuit, directly drives MOSFET. Its maximum peak current is 1.5 A for sink, and 1.5 A for source. (11) Zero current correction circuit Unless multiplier output or current error amplifier input has offset voltage, the input current to converter will be almost zero when PFC converter has completely no load. However, if the offset voltage viewed from IS pin is negative, the input current corresponding to offset voltage might flow to converter even when no load or light load. In such a case, the output voltage of power factor correction converter will rise abnormally because the input current will be excessive. Offset voltage in the IS pin (Visof) is 0 mV. However, the offset voltage of the IS pin against sense resistor voltage may be negative because a voltage will be generated by an external filter resistance connected to the IS pin. Therefore, FA5612/13 has this correction circuit to avoid rising the output voltage when light load with such case. Usual output voltage from error amplifier is 0.5 V or higher. When its output voltage has dropped below 0.5 V, zero current correction circuit operates. Error amplifier output voltage drops below 0.5 V when an input current flows under no or light load on account of offset in multiplier output or current error amplifier input. Then, zero current correction circuit corrects the offset voltage of multiplier output. This function prevents the output voltage of power factor correction converter from rising excessively, so that the output voltage is kept at a constant level. The correction amount varies in a linear function of the output of current error amplifier, thereby ensuring a stable run. Fig. 14 shows effects of zero current correction circuit. Electric Co., Ltd. .0.08Fuji AN-049J Rev.1.0 AN-054E Rev.1.2 Apr.-2011 18 http://www.fujielectric.co.jp/products/semiconductor/ FA5612, FA5613 Consumption diagram of operations when IS pin offset is negative Input current Without zero current correction circuit 軽負荷時補正回路なし With zero current correction circuit 軽負荷時補正回路あり AC 交流入力電流 input current AC 交流入力電流 input current 定格負荷 Rated load No load 無負荷 定格負荷 Rated load Effect by light load 軽負荷時補正回路 による効果 correction circuit オフセットに相当する電流 Current corresponding to offset No load 無負荷 0 時間 Time 交流入力電圧の1/2周期 1/2 cycle of AC input voltage 0 交流入力電圧の1/2周期 1/2 cycle of AC input voltage 時間 Time Without zero current correction circuit 軽負荷時補正回路なし 出力電圧 Vo of power factor correction Output voltage Vo 力率改善コンバータ Output voltage 軽負荷時補正回路あり With light load correction circuit 0 力率改善コンバータ 出力電力 Po Output power Po of power factor correction Fig.14 Effects of zero current correction circuit Electric Co., Ltd. .0.08Fuji AN-049J Rev.1.0 AN-054E Rev.1.2 Apr.-2011 19 http://www.fujielectric.co.jp/products/semiconductor/ FA5612, FA5613 11. Description of use for each pin (1) Terminal No.1 (FB pin) Functions (i) Inputs feedback signal of output voltage setting (ii) Detects FB pin open/short (iii) Detects output overvoltage state Applications (i) Feedback signal input ▪ Wiring Connect the node of dividing resistance for output voltage setting ▪ Operation The PFC output voltage is controlled so that the FB pin voltage will correspond to the internal reference voltage (2.5 V). For FB pin open circuit, FB pin is connected with pull-down resistance in IC inside. Therefore, take its resistance into account when choosing the resistance of R1 and R2 to set the output voltage (Vout). Vout (R2 Rfb) /(R2 Rfb) VREF R1 VREF where: VREF: Reference voltage = 2.5 V (typ.) Rfb: FB pin pull-down resistance = 2.5 MΩ (typ.) To avoid an erratic operation by noises, connect capacitance C3 of 100 to 3300 pF between FB pin and GND. (ii) FB pin open/short detection ▪ Wiring Same as feedback signal input in (i) ▪ Operation When, on account of FB pin open circuit or short circuit of R2 in resistive divider, the FB input voltage has dropped below 0.3 V, the output of comparator (SP) is inverted, thereby stopping the IC output. (iii) Output overvoltage detection ▪ Wiring Same as feedback signal input in (i) ▪ Operation In normal operation, FB pin voltage is almost the same as reference voltage of error amplifier (2.5 V). Like when the output voltage has risen for some reason, if the FB pin voltage reaches comparator reference voltage (1.09*VREF), comparator (OVP) output is inverted to stop OUT pulses. As soon as output voltage returns to a normal level, OUT pulses are recovered. Vout VREF(2.5V) R1 FB VCMP 1 R2 C3 ERRAMP Rfb Open/Short Ｃｏｍｐ SP Vthfb(0.3V) O.V.P Ｄｙｎａｍｉｃ ＯＶＰ Static ＯＶＰ Fig.15 FB pin circuit (2) Terminal No.2 (VCMP pin) Function (i) Phase compensation of output of incorporated voltage error amplifier (ERRAMP) Application (i) Phase compensation of incorporated ERRAMP output ▪ Wiring Connect R and C between COMP and GND as shown in Fig. 16 ▪ Operation COMP pin avoids an appearance of the double frequency ripple of the AC line on the FB pin voltage with connecting R and C. Reference: Example of applied circuit: C4 = 0.47 uF C5 = 2.2 uF R3 = 10 kΩ The above is an example. Determine them upon sufficiently verifying your instrument. VCMP 2 ERRAMP MUL R3 C4 C5 Fig.16 VCMP pin circuit Electric Co., Ltd. .0.08Fuji AN-049J Rev.1.0 AN-054E Rev.1.2 Apr.-2011 20 http://www.fujielectric.co.jp/products/semiconductor/ FA5612, FA5613 Besides, Soft start function is realized by slowing a voltage rise of COMP pin with adjustment of capacitance connected between COMP and GND. When starting, VCMP voltage rises and a switching operation starts at 0.5 V. At this time, MOSFET ON width increases gradually in proportion to the COMP voltage rise. The soft start time is adjustable with adjustment with changing capacitors C4 and C5. Increasing C4, C5 capacitance → prolongs soft start time Decreasing C4, C5 capacitance → shortens soft start time C1 R6 VDET 3 R7 C6 (3) Terminal No.3 (VDET pin) Function (i) Input voltage detection (multiplier input) Application (i) Input voltage setting for VDET pin Multiplier generates current reference signal. Its VDET pin (pin 3) receives sinusoidal full-waveform rectified waveforms. Considering the dynamic range of multiplier operation, VDET pin peak value would be used within 0.65 to 2.4 V. Therefore, set R6 and R7 in Fig. 17 so that the peak voltage of sinusoidal waveforms at VDET pin will be between 0.65 and 2.4 V with the entire range of AC input voltage. Recommended dividing ratio: R6:R7 = 160:1 Fig.17 VDET terminal circuit D1 L1 C1 Q1 C2 Rs Caution: Because multiplier has dispersions of characteristics, even if VDET pin voltage is 2.4 V or lower, multiplier might be saturated and the input peak current would slightly be truncated like trapezoidal waves. R4 C6 IS (4) Terminal No.4 (IS pin) Functions (i) Inductor current detection (ii) Turn off OUT output upon detecting an overcurrent Applications (i) Via IS pin, inductor current signal is applied to current error amplifier (CUR_AMP) that constitutes a current loop for making the input current follow sinusoidal waveforms. CUR_AMP that is connected with multiplier output receives current reference signal. IS pin is current input terminal, and receives a potential of 0 to -0.4 V with respect to GND level. (ii) When IS pin voltage is lower than IS threshold voltage, comparator output signal is inverted to turn off OUT output. ▪ Supplement When MOSFET turns on, MOSFET gate drive current and surge current are generated by discharge of stray capacitance, and then those currents flow to current detecting resistance Rs. An excessively large surge current may cause an erratic operation to disturb the input current waveform. Depending on the surge current intensity, timing, etc., pulse shoots may mix with turn-on parts of IC's OUT pulses. So, RC filter shown in Fig. 18 is connected in generally. Since the level is determined by resistive division as shown in Fig. 18, 100 Ω or lower is recommended for input resistance R4. Rated voltage at IS pin for input of inductor current signal is -5 V. In case of a general boost circuit, a rush current flows for charging the output smoothing capacitance C2 the instant an AC input voltage has been connected. This current may be considerably greater than at a steady operation. As a result, IS pin may receive a voltage that is far higher than usual. Even if such AC voltage is connected, IS pin must not be exposed to a potential higher than -5 V that is an absolute maximum rated voltage. There may be the case that a voltage higher than the rated is applied to IS pin. In such case, it needs to use a preventive circuit for suppression of a rush current or to add the Zener diode to IS pin as shown in Fig. 19. 4 12kΩ IL Detector 28kΩ 5V Fig.18 IS pin circuit D1 L1 C2 Q1 Rs 7 R4 GND ZD FA5610 C6 4 IS Fig.19 IS pin circuit (2) Electric Co., Ltd. .0.08Fuji AN-049J Rev.1.0 AN-054E Rev.1.2 Apr.-2011 21 http://www.fujielectric.co.jp/products/semiconductor/ FA5612, FA5613 Caution: Maximum power design It needs a notice about a setting of the sense resistance to output maximum power at whole input condition because a power limitation may occur by IC functions. Fig. 20 shows a block diagram concerning the input current control. The VDET voltage is relatively high at high RMS input voltage, and the input current is limited by OCP function shown in the path B of Fig. 20 in such case. (Reference figure is shown in Fig. 21.) The VDET voltage is relatively low at the low RMS input voltage, and the maximum output voltage of multiplier is low too. So, the input current is limited by the multiplier shown in the path A of Fig. 20 in such case. (Reference figure is shown in Fig. 22.) This means that the maximum inductor current is limited by an above function unless the reasonable sense resistance is chosen. Therefore, it needs to choose the sense resistor Rs which satisfies each condition shown in the next page. M _OUT = K × A × B VDET A VCM P B CUR. AMP M_OUT Multiplier ICMPcurrent 電流 ICMP ICMP A 5V PWM COMP 28kΩ IL_DET IL Detector Gate Driver OSC 12kΩ OUT B O.C.P インダクタ最大電流 Maximum inductor current Maximum inductor current インダクタ最大電流 Fig.20 Current control area block diagram Fig.20 Current control area block diagram IS OCP Limited by multiplier OCPに達する前に before reaching OCP 乗算器で制限される。 時間 Time OCP 時間 Time Fig.21 Maximum inductor current at high input voltage Fig.22Maximum inductor current at low input voltage Inductor current インダクタ電流 Note that the limitation of maximum inductor current is different as shown in Fig. 23 according to whether by OCP or by multiplier. ▪ By OCP: Current peaks including switching ripples are subjected to limitation. ▪ By multiplier: Current excluding switching ripples is subjected to limitation. インダクタ最大電流 Maximum inductor current Detail 拡大 時間 Time Limitation by OCP OCPによる制限 (cover switching ripples) (スイッチングリップル含む) 乗算器による制限 Limitation by multiplier (スイッチングリップル (do not cover switching ripples) 含まない) 時間 Time Fig.23 Maximum current limitation Electric Co., Ltd. .0.08Fuji AN-049J Rev.1.0 AN-054E Rev.1.2 Apr.-2011 22 http://www.fujielectric.co.jp/products/semiconductor/ FA5612, FA5613 Design current detecting resistance Rs so as to meet a maximum power in the input voltage range, and also to clear 2 power limiting conditions below (Fig. 24). (1) Power limitation by multiplier Design current detecting resistance Rs so that VIS voltage (mean) will be -0.33 V or greater that is maximum of item “ IS pin voltage (Vis_054) “. In case of settling as output power Po (W), efficiency η, and minimum input voltage Vacmin (V), maximum inductor current Iinmax (A) is given by following equation. Po Iinmax 2・ η Vacmin Vis_054 (-0.33Vmax) VIS voltage (mean) will be -0.33 V or higher when: Po Rs 2・ η Vacmin VIS VIS(平均値） (mean) VIS (peak) VIS(ピーク値） Vocpl (-0.475Vmax) VIS（V) Rs Iinmax ＞ - 0.33V ＞ 0.33V VDET（V) 0.54V ①乗算器による制限 (1) By multiplier ②過電流ｽﾚｯｼｭによる制限 (2) By overcurrent threshold Fig.24 Maximum power limitation Therefore, design current detecting resistance Rs (Ω) so as to meat: Rs ＜ 0.33 η Vacmin 2 Po (Ω) ..... (1) (2) Power limitation by OCP Design current detecting resistance Rs so that VIS voltage (peak) will be -0.475 V or greater that is maximum of IS threshold voltage (Vocpl). In case of settling as ripple current Iripple (A), switching frequency fsw, output voltage Vout, boost inductance L, and ON duty D, ON duty D is given by following equation. D Vout 2 Vac min Vout VIS voltage (peak) will be -0.475 V or higher when: Rs (Iinmax Iripple ) 2 2 Po Rs ( η Vacmin ＞ - 0.475V 2 Vac min D )＞ 0.475V 2 fsw Ｌ Therefore, design current detecting resistance Rs (Ω) so as to meat: Rs＜ 0.475 2 Po Vac min D η Vacmin 2 fsw Ｌ (Ω) ..... (2) In order to output maximum power at a minimum input voltage, therefore, select Rs determined by expression (1) or (2), whichever smaller. Caution: To define a current limitation by multiplier, select the voltage at VDET pin so as to be 0.54 V or higher even at a minimum input voltage. Electric Co., Ltd. .0.08Fuji AN-049J Rev.1.0 AN-054E Rev.1.2 Apr.-2011 23 http://www.fujielectric.co.jp/products/semiconductor/ FA5612, FA5613 (5) Terminal No. 5 (ICMP pin) Function (i) Phase compensation for output of incorporated current error amplifier (CUR_AMP) Application (i) Phase compensation for output of incorporated CUR_AMP ▪ Wiring Connect R and C between ICMP and GND as shown in Fig. 25. ▪ Operation R and C are connected to ICMP pin to block ripple components of switching frequency that could otherwise appear on IS pin input. (Reference) Example of applied circuit: C8 = 100 pF C9 = 680 pF R8 = 47 kΩ The above is an example. Determine them upon sufficiently verifying your instrument. ICMP 5 R8 CUR_AMP PWM_COMP C8 C9 Fig.25 ICMP pin circuit (6) Terminal No. 6 (GND pin) Function Constitutes the reference of each part of IC. (7) Terminal No. 7 (OUT pin) Functions (i) Drives MOSFET (ii) Sets oscillation frequency Fig.26 OUT pin circuit (1) Applications (i) Drive of MOSFET ▪ Wiring Connected via resistance Ro to gate terminal of MOSFET ▪ Operation Goes high when MOSFET is turned on. Nearly VCC voltage is outputted. Goes low when MOSFET is turned off. Voltage of nearly 0 V is outputted. ▪ Supplement Connect a gate resistance for current limitation at OUT pin, prevention of oscillation of gate terminal voltage, etc. Rated output currents of IC: Source ... 1.5 A, sink ... 1.5 A. Connection in Fig. 27 or 28 allows to distinctly set the gate drive currents for turning on and off MOSFET. Fig.27 OUT pin circuit (2) (ii) Setting of oscillation frequency ▪ Wiring (1) Ordinary connection Connect resistance Rg between MOSFET gate and GND if no buffer is connected on IC output as shown in Fig. 26, 27 and 28. According to resistance Rg, switching frequency can be selected out of 3 different modes given in table below. Mode1 Frequency diffusion Mode2 65kHz fixed Mode3 60kHz fixed Resistance Rg Accuracy Temperature characteristics 4.7kΩ 12kΩ 13kΩ 27kΩ ±5%max ±2%max ±5%max ±5%max 200ppm/°Cmax 200ppm/°Cmax 200ppm/°Cmax 200ppm/°Cmax Fig.28 OUT pin circuit (3) * Ro: 100 Ω max. Caution: ▪ Resistance Ro between OUT pin and FET gate must be 100 Ω or less ▪ If mode 3 is selected (27 kΩ used), starting up the frequency setting raises the OUT-GND voltage up to 1.4V Electric Co., Ltd. .0.08Fuji AN-049J Rev.1.0 AN-054E Rev.1.2 Apr.-2011 24 http://www.fujielectric.co.jp/products/semiconductor/ FA5612, FA5613 (2) If buffer is connected on IC output If buffer is connected on IC output, select a configuration shown in Fig. 29, and select the frequency setting resistance as given in table below. Mode1 Jittering Resistance Rg 4.7kΩ ±5%max Temperature characteristics 200ppm/°Cmax Mode2 65kHz fixed 13kΩ ±5%max 200ppm/°Cmax Mode3 60kHz fixed 30kΩ ±5%max 200ppm/°Cmax Accuracy * Ro: 100 Ω max. If combined resistance connected on buffer output is Rx, set Rx to 3 kΩ or higher taking into account dispersion and temperature characteristics. Vcc R11 R12 OUT Ro 7 R21 Rg R22 Fig.29 Buffer Combined 合成抵抗Rx resistance Rx Example: Select R11 = 10 Ω, and R12 = 10 kΩ. Suppose their resistance may change by 10% maximum on account of their dispersion and temperature characteristics. If 3 of them each are connected in parallel, Rx = 10.01 kΩ × 90% ÷ 3 = 3.003 kΩ holds, thereby clearing the requisite. Caution: ▪ Resistance Ro between OUT pin and buffer must be 100 Ω or less ▪ If mode 3 is selected (30 kΩ used), starting up the frequency setting raises the OUT-GND voltage up to 1.2 V ▪ Above conditions presuppose hFE of transistor used in buffer is 50 minimum, and that Vbe is 0.3 V maximum taking the temperature characteristics into account. Unless characteristics of a particular transistor to use clear the requisites, set the frequency resorting to a method in “(3) Other circuit configuration.” (3) Other circuit configuration Unless the circuit configuration connected to OUT pin clears the specifications in (1) nor (2), determine the frequency based on the current and voltage defined by specified frequency setting. ( See p. 15 Fig. 5 Frequency setting circuit ) Be sure to take into account the IC characteristics, and dispersion and temperature characteristics of parts connected to OUT pin. General precaution about frequency setting: In setting the frequency, make sure, in addition to respecting our recommendations in (1) and (2) above, there is no problem of influences by dispersion and temperature characteristics of your resistors, wiring, noise (influence of auxiliary power supply that operates before PFC starts, in particular) and other matters than resistance itself based on the current and voltage regarding the specified frequency setting. In setting of the frequency, please confirm whether there is no bad influence of following items including our setting recommendation and our setting specification. - Dispersion of or the temperature characteristic of resistance used, a design of wiring, noise (especially from sub power supply before the PFC start operation), etc. Electric Co., Ltd. .0.08Fuji AN-049J Rev.1.0 AN-054E Rev.1.2 Apr.-2011 25 http://www.fujielectric.co.jp/products/semiconductor/ FA5612, FA5613 (8) Terminal No. 8 (VCC pin) Function (i) Supplies IC with power Application (i) Supplies IC with power ▪ Wiring Connect a startup resistance between rectified voltage line and VCC pin. Generally, connect a rectified and smoothed voltage from auxiliary winding provided on transformer. Or connect an external DC source. ▪ Operation At the time of startup in case VCC voltage is obtained from auxiliary winding, the current via the startup resistance charges the smoothing capacitance and, when the level rises up to UVLO ON threshold voltage, IC starts up. Immediately before startup, a current of at least 110 uA (max.) that is a startup current for IC must be fed. During a steady operation, VCC is supplied from inductor's auxiliary winding (Fig. 30). As the source voltage rises from zero, the operation starts at 9.6 V (typ.) for FA5612, or at 13 V (typ.) for FA5613. Any of started-up ICs stops operating when the source voltage drops down to 9 V (typ.) While IC stops operation by under voltage lockout circuit, OUT pin keeps low level and shuts the output of power supply off. Supplement: Under voltage lockout function avoids an erratic operation of circuit when source voltage has dropped. Noise applied to VCC pin will cause an erratic operation. To avoid the noise, connect a capacitance near VCC pin whether IC is operated by another source or not. Determine the capacitance so that the noise generated on VCC pin will be within ±0.6 V, and make doubly sure no erratic operation occurs by noise (Fig. 31). 8 VCC Fig.30 VCC pin circuit (1) 8 External DC source 外部DC電源 VCC Fig.31 VCC pin circuit (2) Electric Co., Ltd. .0.08Fuji AN-049J Rev.1.0 AN-054E Rev.1.2 Apr.-2011 26 http://www.fujielectric.co.jp/products/semiconductor/ FA5612, FA5613 12. Advice for design (1) Advice in pattern designing Main circuit MOSFET, inductor, diodes, etc. perform switching under high voltage and large current. If wiring of IC or signals inputted to IC gets too near such main circuit parts, they may operate erratically upon being affected by noise generated there. Attention must be paid particularly in following cases (examples of faulty cases). ▪ IC is arranged under inductor or other main circuit parts, or immediately behind main circuit parts on double sided circuit board (Fig. 32) ▪ IC is arranged close to inductor, MOSFET or diode (Fig. 33) ▪ Signal wiring is placed under inductor or near MOSFET or diode (Fig. 34) IC is arranged under inductor インダクタの下(基板の裏面の場合 (or on immediately opposite side on circuit board) も含む）にICが配置されている。 Fig.32 Example of inadvisable arrangement (1) IC is arranged close to inductor or MOSFET インダクタやMOSFETのすぐ近くに インダクタの下やMOSFETのすぐ近く Signal wiring passes under inductor を信号の配線が通過している。 or close to MOSFET ICが配置されている。 Fig.33 Example of inadvisable arrangement (2) Fig.34 Example of inadvisable pattern (2) Typical GND wiring in IC area To minimize influences on IC of noises from main circuit, separate GND of IC and signal lines for parts of IC area, and GND of PFC main circuit away from each other, and connect them via one point near current detecting resistance Rs and output capacitance. IS signal whose voltage level is low is liable to noise. Minimize lengths of IS pin-Rs and Rs-GND wiring. Arrange VCC-GND capacitance close to IC. Otherwise, the effect will be poor. Arrange the capacitance between IC area input terminal and GND close to IC. It also has a function of noise elimination and, if away from IC, it will be affected by noise. Caution: Wiring is exemplified for you to understand how to connect the GND line. Noise and incidental erratic operations differ from one instrument to another. Adopting any wiring exemplified in Fig. 35 will not necessarily guarantee normal operations of your instruments. Electric Co., Ltd. .0.08Fuji AN-049J Rev.1.0 AN-054E Rev.1.2 Apr.-2011 27 http://www.fujielectric.co.jp/products/semiconductor/ FA5612, FA5613 Rs IS VDET VCMP FB FA5612 /FA5613 ICMP GND OUT VCC Fig.36 Example of inadvisable GND wiring (GND is common to signal line parts and main circuit) Fig.35 Example of advisable GND wiring Rs Drive current when turning on IS VDET VCMP FB Drive current ターンオン時 when turning on 駆動電流 FA5612 /FA5613 ICMP GND OUT VCC Fig.37 Example of inadvisable GND wiring Fig.38 Example of GND wiring (Liable to noise when turning on if GND is (GND of VCC capacitance is common to VCC capacitance and signal line) distinct from signal line GND) Electric Co., Ltd. .0.08Fuji AN-049J Rev.1.0 AN-054E Rev.1.2 Apr.-2011 28 http://www.fujielectric.co.jp/products/semiconductor/ FA5612, FA5613 (3) Precautions in use regarding terminal noise If noise is applied to any IC pin, an erratic operation may be caused. Proceed to design upon respecting the precautions below. Condition Pin FB Malfunction in fear Input regulations Cautions in design switching may stop when noise is over over voltage protection level input signal is only for connect IC may become stanbay mode when noise is under short detection level feedback terminal pin offset occurs in output voltage and output voltage rises or falls output voltage output of multiplier output becomes unstable, and input current waveform may cancel noise voltage of confirm disturbed condenser sufficiently near phase compensation constant VCMP switching may become when noise is over threshold voltage switching may stop when noise is under threshold voltage output of multiplier output becomes unstable, and input current waveform may be cancel noise connect condensor near pin cancel noise connect condensor near pin cancel noise confirm VDET Input noise disturbed (within absolute current may be detected incorrectly IS maximum ratings) It may turn off when noise is over overcurrent protection level because a duty changes, input current waveform may be disturbed sufficiently phase ICMP compensation constant reference voltage changes, IC may not behave normally cancel noise ground wiring should be a GND wide wiring the output may fall not to be able to drive Mos normally when signals more than the cancel noise OUT ability of the driver are input IC may stop when noise under UVLO is input don't input noise under connect condensor near pin VCC UVLO when moving FB a parasitism element works, and the malfunction such as IC stop may occur don't input minus voltage VCMP less than maximum VDET absolute voltage Input minus voltage ICMP (less than absolute VCC maximum voltage) IS IC may be destroyed OUT IC may be destroyed VCC a parasitism element works, and the malfunction such as IC stop may occur FB IC may be destroyed don't input minus voltage VCMP more Input plus voltage VDET absolute voltage (more than absolute ICMP maximum voltage) IS OUT than maximum gnd level may be changed IC may be destroyed VCC Electric Co., Ltd. .0.08Fuji AN-049J Rev.1.0 AN-054E Rev.1.2 Apr.-2011 29 http://www.fujielectric.co.jp/products/semiconductor/ FA5612, FA5613 13. Example of application circuit ( 390V / 1.5A output ) Electric Co., Ltd. .0.08Fuji AN-049J Rev.1.0 AN-054E Rev.1.2 Apr.-2011 30 http://www.fujielectric.co.jp/products/semiconductor/