Application Note, V1.1, October 2009 EVALPFC2-ICE2PCS01 300W PFC Evaluation Board with CCM PFC controller ICE2PCS01 Power Management & Supply N e v e r s t o p t h i n k i n g . Edition 2009-10-13 Published by Infineon Technologies Asia Pacific, 168 Kallang Way, 349253 Singapore, Singapore © Infineon Technologies AP 2004. All Rights Reserved. Attention please! The information herein is given to describe certain components and shall not be considered as a guarantee of characteristics. Terms of delivery and rights to technical change reserved. We hereby disclaim any and all warranties, including but not limited to warranties of non-infringement, regarding circuits, descriptions and charts stated herein. Information For further information on technology, delivery terms and conditions and prices please contact your nearest Infineon Technologies Office (www.infineon.com). Warnings Due to technical requirements components may contain dangerous substances. For information on the types in question please contact your nearest Infineon Technologies Office. Infineon Technologies Components may only be used in life-support devices or systems with the express written approval of Infineon Technologies, if a failure of such components can reasonably be expected to cause the failure of that life-support device or system, or to affect the safety or effectiveness of that device or system. Life support devices or systems are intended to be implanted in the human body, or to support and/or maintain and sustain and/or protect human life. If they fail, it is reasonable to assume that the health of the user or other persons may be endangered. EVALPFC2-ICE2PCS01 Revision History: Previous Version: Page 9&10 2009-10 V1.0 Subjects (major changes since last revision) Capacitor CX1 size changed 300W PFC Evaluation Board with CCM PFC controller ICE2PCS01 License to Infineon Technologies Asia Pacific Pte Ltd AN-PS0010 Liu Jianwei Luo Junyang Jeoh Meng Kiat We Listen to Your Comments Any information within this document that you feel is wrong, unclear or missing at all? Your feedback will help us to continuously improve the quality of this document. Please send your proposal (including a reference to this document) to: [email protected] 3 Table of Content 1 Content................................................................................................................. 5 2 Evaluation Board ................................................................................................ 5 3 Technical Specifications .................................................................................... 6 4 Circuit Description.............................................................................................. 6 5 Circuit Operation................................................................................................. 6 6 Circuit Diagram ................................................................................................... 8 7 PCB Layout Top Layer ....................................................................................... 9 8 PCB layout Bottom Layer................................................................................. 10 9 Component List................................................................................................. 11 10 Boost Choke Layout ....................................................................................... 122 11 Test report ......................................................................................................... 12 11.1 11.2 11.3 Load test (table and figure).............................................................................. 12 Harmonic test according to EN61000-3-2 Class D requirement .................. 14 Test Waveforms ................................................................................................ 15 12 References:........................................................................................................ 16 4 1 Content The evaluation board described here is a 300W power factor correction (PFC) circuit with 85~265VAC universal input and 393VDC fixed output. Boost converter topology is employed in this board. The continuous conduction mode (CCM) PFC controller ICE2PCS01 is employed in this board to achieve the unity power factor. The switching frequency is programmable by external resistor at one pin. There are various protection features incorporated to ensure safe system operation conditions. The device has a unique soft-start function which limits the start up inrush current thus reducing the stress on the boost diode. To improve the efficiency, the third generation CoolMOS™ is used as the power switch due to its lowest area specific Rdson. High voltage Silicon Carbide (SiC) Schottky diode thinQ!™ is used as PFC boost diode. Because of its ideal reverse recovery behavior, SiC Schottky diode is extremely suitable for high frequency CCM PFC application. 2 Evaluation board 5 3 Technical specifications: Input voltage Input frequency Output voltage and current Output power Efficiency Switching frequency 85VAC~265VAC 50Hz 393VDC, 0.75A ~ 300W >90% at full load 62.5kHz (with R8=76K) 4 Circuit Description Line Input The AC line input side comprises the input fuse F1 as over-current protection. The high frequency current ripple is filtered by R1, L1 and CX1. The choke L2, X2-capacitors CX1 and CX2 and Y1capacitor CY1 and CY2 are used as radio interference suppressors. RT1 is placed in series to limit inrush current during each power on. Power Stage − Boost Type PFC Converter After the bridge rectifier BR1, there is a boost type PFC converter consisting of L3, Q1, D1 and C2. The third generation CoolMOS™ is used as the power switch Q1. Due to its low Rdson, the small heat sink can fulfill the dissipation requirement. SiC Schottky diode thinQ!™ is used for D1. As SiC Schottky diode does not show a reverse recovery behavior, the stress on the MOSFET will be reduced due to very low current spike during turn on transient. Simultaneously higher reliability of the entire system can be achieved. However, due to the poor pulse current capability of SiC Schottky diode, a standard diode D2 is necessary to bypass the high inrush current during each power on transient. Output capacitor C2 provides energy buffering to reduce the output voltage ripple (100Hz) to the acceptable level. PWM control of Boost Converter The PWM control is realized by 8-Pin CCM PFC IC ICE2PCS01. Unlike the conventional PFC controller, ICE2PCS01 does not need direct sine wave reference signal. The switching frequency is fixed and programmed by R8. There are two control loops in the circuit, voltage loop and current loop. The output voltage is sensed by the voltage divider of R5A, R5B, R6A and R6B and sent to internal error amplifier. The output of error amplifier is used to control current in the inner current loop. The compensation network C4, C5, R7 constitutes the external circuitry of the error amplifier. This circuitry allows the feedback to be matched to various load conditions, thereby providing stable control. In order not to make the response for 100Hz ripple, the voltage loop compensation is implemented with low bandwidth. The inner loop, current control loop, is implemented with average current mode strategy. The instant current is adjusted to be proportional to both of MOSFET off duty DOFF and the error amplifier output voltage of voltage loop. The current is sensed by shunt resistors R2, R2A and R2B and fed into IC through R9. The current sense signal is averaged by an internal operating amplifier and then processed in the PWM generator which drives the gate drive. The averaging is realized by charging and discharging an external capacitor C7. The IC supply is provided by external voltage source and filtered and buffered by C8 and C9. The IC output gate driver is a fast totem pole gate drive. It has an in-built cross conduction current protection and a Zener diode to protect the external transistor switch against undesirable over voltages. The gate drive resistor R4 is selected to limit and gate pulse current and drive MOSFET for fast switching. 5 Circuit Operation Soft Start When Vcc pin is higher than turn-on threshold, typical 11V, PFC is going to start. The unique soft start is integrated. Input current keeps sinusoidal and is increasing gradually until output voltage reaches 6 75% of rating. Because the peak current limit is not activated, the boost diode is not stressed with large diode duty cycle under high current. Enhanced Dynamic Response Due to inherent low bandwidth of PFC dynamic, in case of load jump, regulation circuit can not response fast enough and it will lead to large output voltage overshoot or drop. To solve this problem in PFC application, enhance dynamic response is implemented in the IC. Whenever output voltage exceeds by ±5%, it will bypass the slow compensation operating amplifier and act on the nonlinear gain block to affect the duty cycle directly. The output voltage can be recovered in a short time. Protection Features a. Open loop protection (OLP) / Mains under voltage protection The open loop protection is available for this IC to safe-guard the output. Whenever VSENSE voltage falls below 0.6V, or equivalently VOUT falls below 20% of its rated value, it indicates an open loop condition (i.e. VSENSE pin not connected). In this case, most of the blocks within the IC will be shutdown. It is implemented using a comparator with a threshold of 0.6V. Insufficient input voltage VIN will also trigger this protection. b. Output over-voltage protection Output over-voltage protection is also available by the same integrated blocks of enhanced dynamic response. Whenever VOUT exceeds the rated value by 5%, the over-voltage protection OVP is active. This is implemented by sensing the voltage at pin VSENSE with respect to a reference voltage of 3.15V. A VSENSE voltage higher than 3.15V will immediately reduce the output duty cycle even down to zero, bypassing the normal voltage loop control. This results in a lower input power and the output voltage VOUT is reduced. c. Soft over current control (SOC) and peak current limit When the amplitude of current sense voltage reaches 0.68V, Soft Over Current Control (SOC) is activated. This is a soft control does not directly switch off the gate drive but acts on the internal blocks to result in a reduced PWM duty cycle. The IC also provides a cycle by cycle peak current limitation (PCL). It is active when the voltage at current sense voltage reaches -1.04V. The gate output is immediately off after 300ns blanking time. d. IC supply under voltage lock out When VCC voltage is below the under voltage lockout threshold VCCUVLO, typical 11V, IC is off the gate drive is internally pull low to maintain the off state. The current consumption is down to 200uA only. 7 6 Circuit Diagram 1 2 4 3 D D D2 1N5408 F1 5A L 85~265VAC N VAR1 S10K275 R1 120ohm L2 L1 40uH CX1 CY1 2.2nF, Y2, 250V Earth C C2 C1 0.1u/630V R2 0.33/1W 0.47u/275V 0.47u/275V 390V/300W Vo Q1 SPP20N60C3 CX2 2*3.9mH D1 SDP04S60 L3 1.24mH BR1 8A, 400V RT1 S237/5 CY2 2.2nF, Y2, 250V R3 10k Gnd R2A 0.22/1W C R5 390k, 1% R2B 0.22/1W R4 R5A 220 3.3 390k, 1% 3 R9 IC? I-Sense 7 B 2 Vcc ICE2PCS01 I-Comp Freq 8 Gate GND Vsense 6 V-Comp 5 R7 GND 47u/25V 0.1u C7 4.7nF R8 76k 33k 1 C8 4 Vcc C9 B C5 C4 0.1uF C3 0.1uF R6 R6B 10k, 1% 15k,1% 1uF A A 1 2 3 8 4 7 PCB layout top layer 9 8 PCB layout Bottom: 10 9 Component List: Designator Part Type Description Manufacturer / Part No. BR1 C1 C2 C3 C4 C5 C7 C8 C9 CX1 CX2 CY1 CY2 8A, 400V 0.1uF/630V 220uF/450V 0.1uF/50V 0.1uF/50V 1uF/50V 4.7nF/50V 0.1uF/50V 47uF/25V 0.47uF, X1, 305V 0.47uF, X1, 305V 2.2nF, Y2, 250V 2.2nF, Y2, 250V Vishay / KBU8G Epcos / B32652A6104J Epcos / B43304C5227M D1 D2 F1 SDT04S60 1N5408 5A Bridge Rectifier Ceramic Cap Electrolytic Cap Ceramic Cap Ceramic Cap Ceramic Cap Ceramic Cap Ceramic Cap Electrolytic Cap Ceramic Cap Ceramic Cap Ceramic Cap Ceramic Cap Connector Diode Diode Fuse Fuse Holder IC1 JP1 JP2 JP3 JP4 L1* L2 L3 Q1 ICE2PCS01 12.5mm, Ф0.7mm 20mm, Ф0.7mm 12mm, Ф1.2mm 17.5mm, Ф0.7mm Shorted 2*3.9mH 1.24mH SPP20N60C3 R2 R2A R2B R3 R4 R5A R5B R6A R6B R7 R8 R9 RT1 VAR1 0.33/1W, 5% 0.22/1W, 5% 0.22/1W, 5% 10k/0.25W, 5% 3.3/0.25W, 5% 390k/0.25W, 1% 390k/0.25W, 1% 10k/0.25W, 1% 15k/0.25W, 1% 33k/0.25W, 5% 75k/0.25W, 1% 220/0.25W, 5% S237/5 S10K275 Murata / RPER71H104K2K1A03B Murata / RPER71H104K2K1A03B Murata / RPER71H104K2K1A03B Epcos / B32922C3474M Epcos / B32922C3474M Epcos / B81123C1222M000 Epcos / B81123C1222M000 Vishay / 1N5408 Infineon Jumper Jumper Jumper Jumper CM Choke Choke Power MOSFET Heat Sink TO220 Clip TO247 Clip TO220 Isolation Pad 3mm Screw Metal Film Resistor Metal Film Resistor Metal Film Resistor Carbon Film Resistor Carbon Film Resistor Carbon Film Resistor Carbon Film Resistor Carbon Film Resistor Carbon Film Resistor Carbon Film Resistor Carbon Film Resistor Carbon Film Resistor NTC Thermistor Varistor 11 Epcos / B82725J2602N20 Infineon Epcos / B57237S509M Epcos / B72210S271K101 10 Boost Choke Layout Core: CS468125 toriod Wire: 1 x Φ1.0mm, AWG19 Turns: 83 Inductance: L=1.24mH 11 Test report 11.1 Load test (table and figure): Vin Pin (W) Iin (A) Vout (V) (VAC) 320 3.8 393 211 2.51 393 165 1.96 393 124 1.47 393 83 0.99 393 43 0.52 394 31 0.39 394 20.3 0.26 395 12.2 0.17 396 85 4.2 0.07 396 316 2.9 393 208 1.91 393 163 1.5 393 123 1.13 393 83 0.77 393 42.3 0.4 393 30 0.29 394 22 0.22 394 14.2 0.15 394 110 6.2 0.076 394 307 1.4 394 204 1 394 161 0.8 394 120 0.63 394 82 0.45 394 41 0.29 394 29.5 0.16 395 21.7 0.133 395 14 0.1 395 220 6 0.093 395 265 305 1.2 394 203 0.79 394 161 0.63 394 120 0.48 395 81 0.34 395 41 0.21 395 Iout (A) 0.75 0.5 0.4 0.3 0.2 0.1 0.075 0.049 0.029 0.01 0.75 0.5 0.4 0.3 0.2 0.1 0.0718 0.0525 0.034 0.014 0.75 0.5 0.4 0.3 0.2 0.1 0.072 0.053 0.033 0.014 0.75 0.5 0.4 0.3 0.2 0.1 12 Pout (W) 294.75 196.5 157.2 117.9 78.6 39.4 29.55 19.355 11.484 3.96 294.75 196.5 157.2 117.9 78.6 39.3 28.2892 20.685 13.396 5.516 295.5 197 157.6 118.2 78.8 39.4 28.44 20.935 13.035 5.53 295.5 197 157.6 118.5 79 39.5 efficiency 92% 93% 95% 95% 95% 92% 95% 95% 94% 94% 93% 94% 96% 96% 95% 93% 94% 94% 94% 89% 96% 97% 98% 99% 96% 96% 96% 96% 93% 92% 97% 97% 98% 99% 98% 96% PF 1 1 1 0.99 0.99 0.97 0.95 0.91 0.87 0.71 1 0.99 0.99 0.99 0.98 0.94 0.89 0.86 0.82 0.63 0.99 0.99 0.97 0.95 0.92 0.83 0.77 0.67 0.53 0.22 0.99 0.98 0.97 0.95 0.91 0.73 29.5 21.7 13.8 5.83 0.17 0.16 0.15 0.1 395 395 395 395 0.072 0.053 0.033 0.014 96% 96% 94% 95% 28.44 20.935 13.035 5.53 0.64 0.45 0.38 0.15 98.0% 300W Load 200W Load 150W Load 80W Load 94.0% 92.0% 90.0% 88.0% 85 110 220 265 Input Voltage (V) 1 0.9 0.8 0.7 85VAC 0.6 PF Efficiency 96.0% 110VAC 0.5 230VAC 0.4 265VAC 0.3 0.2 0.1 0 0 50 100 150 200 Pout (W) 13 250 300 11.2 Harmonic test according to EN61000-3-2 Class D requirement 85VAC, full load (300W output) Iin 85VAC, 9% of full load (28W output) Iin 265VAC, full load (300W output) Iin 14 265VAC, 9% of full load (28W output) Iin 11.3 Waveforms (soft start, load jump, open loop) Soft start, test at 85VAC, Iout=0.2A Iin Vout Vcc Vcomp Load jump test at 85VAC, Iout from 0A to 0.75A Load jump test at 85VAC, Iout from 0.75A to 0A Vgate Vgate Vout Vout Iout Iout 15 Open loop test at 265VAC, Iout=0.1A Vgate Iin Vout Vsense 12 References: 16