Application Note, V2.0, March 2006 EVALPFC2-ICE1PCS01 300W PFC Evaluation Board with CCM PFC controller ICE1PCS01 Power Management & Supply N e v e r s t o p t h i n k i n g . Edition 2006-03-27 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-ICE1PCS01 Revision History: Previous Version: Page 4 - 16 4 - 16 2006-03 V2.0 V1.0 Subjects (major changes since last revision) Switching frequency PCB layout 300W PFC Evaluation Board with CCM PFC controller ICE1PCS01 License to Infineon Technologies Asia Pacific Pte Ltd Junyang Luo Jeoh Meng Kiat Jianwei Liu 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 300W CCM PFC Evaluation Board with ICE1PCS01, CoolMOS™ and SiC Diode thinQ!™ The board described here was designed as a typical power factor correction (PFC) circuit in boost topology. The controller ICE1PCS01 chip used for this application is an 8-pin wide range input IC for active PFC converters. The IC operates in the CCM with average current control and in DCM only under light load condition. 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. Evaluation board 4 Technical specifications: Input voltage Input frequency Output voltage and current Output power Efficiency Switching frequency 85VAC~265VAC 50Hz 400VDC, 0.75A 300W >90% at full load 62.5kHz 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 ICE1PCS01. Unlike the conventional PFC controller, ICE1PCS01 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 R5, R5A, R5B and R6 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. Circuit Operation Soft Start When Vcc pin is higher than turn-on threshold, typical 11.2V, PFC is going to start. The unique soft start is integrated. Input current keeps sinusoidal and is increasing gradually until output voltage 5 reaches 80% 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 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 0.8V, or equivalently VOUT falls below 16% 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 0.8V. Insufficient input voltage VIN will also trigger this protection. 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 5.25V. A VSENSE voltage higher than 5.25V 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. Soft over current control (SOC) and peak current limit When the amplitude of current sense voltage reaches 0.73V, 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 -1.08V. The gate output is immediately off after 300ns blanking time. IC supply under voltage lock out When VCC voltage is below the under voltage lockout threshold VCCUVLO, typical 10.2V, IC is off the gate drive is internally pull low to maintain the off state. The current consumption is down to 200uA only. 6 Circuit Diagram 1 2 3 4 D D D2 1N5408 L 85~265VAC N F1 5A VAR1 S10K275 R1 120ohm L2 L1 40uH CX1 C1 0.1u/630V R2 0.33/1W 0.47u/275V 0.47u/275V CY1 2.2nF, Y2, 250V Earth C Q1 SPP20N60C3 CX2 2*3.9mH D1 SDP04S60 L3 1.24mH BR1 8A, 400V RT1 S237/5 CY2 2.2nF, Y2, 250V 390V/300W Vo C2 R3 10k Gnd R2A 0.22/1W C R5 300k, 1% R2B 0.22/1W R4 R5A 220 3.3 270k, 1% 3 R9 I-Sense 7 B 2 Vcc ICE1PCS01 I-Comp Freq GND Vsense 6 V-Comp 5 B R7 C8 47u/25V 0.1u C7 1nF R8 76k 33k 1 C9 4 Vcc GND R5B 200k, 1% 8 Gate C5 C4 0.1uF C3 470p R6 10k, 1% 1uF A A 1 2 3 4 7 PCB layout top layer 8 PCB layout Bottom: 9 Component List: Designator Part Type Description BR1 C1 C2 C4 C5 C7 C8 C9 CX1 CX2 CY1 CY2 8A, 400V 0.1uF/630V 220uF/450V 0.1uF/50V 1uF/50V 1nF/50V 0.1uF/50V 47uF/25V 0.47uF, X1, 275V 0.47uF, X1, 275V 2.2nF, Y2, 250V 2.2nF, Y2, 250V D1 D2 F1 SDT04S60 1N5408 5A Bridge Rectifier Ceramic Cap Electrolytic 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 ICE1PCS01 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 R5 R5A R5B R6 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% 300k/0.25W, 1% 270k/0.25W, 1% 200k/0.25W, 1% 10k/0.25W, 1% 33k/0.25W, 5% 76k/0.25W, 1% 220/0.25W, 5% S237/5 S10K275 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 Quantity 1 1 1 1 1 1 1 1 1 1 1 1 3 1 1 1 2 1 1 1 1 1 0 1 1 1 1 2 1 2 3 1 1 1 1 1 1 1 1 1 1 1 1 1 1 10 Boost Choke Layout Core: CS468125 toriod Turns: 83 Wire: 1 x Φ1.0mm, AWG19 Inductance: L=1.24mH Test report Load test (table and figure): Vin (VAC) Pin (W) 320 253 209 167 124 82 40 26 19 11 85 7.2 316 248 206 165 123 82 39 27 19 11 110 7.2 307 246 205 164 124 83 43 25.6 17.4 13.5 220 6.7 265 305 244 203 162 122 82 42 Iin (A) 3.8 3 2.5 2 1.5 0.99 0.51 0.37 0.29 0.18 0.13 2.9 2.3 1.9 1.5 1.2 0.78 0.43 0.31 0.24 0.15 0.11 1.4 1.2 1 0.8 0.63 0.45 0.29 0.21 0.15 0.13 0.093 1.2 0.96 0.81 0.67 0.52 0.39 0.26 Vout (V) 399 399 399 399 399 399 399 399 399 399 399 399 399 399 399 399 399 399 399 399 399 399 399 399 399 399 399 399 399 399 399 399 399 399 399 399 399 399 399 399 Iout (A) 0.75 0.59 0.49 0.39 0.29 0.19 0.09 0.06 0.043 0.024 0.015 0.75 0.59 0.49 0.39 0.29 0.19 0.09 0.06 0.043 0.024 0.015 0.75 0.6 0.5 0.4 0.3 0.25 0.2 0.1 0.04 0.03 0.015 0.75 0.6 0.5 0.4 0.3 0.2 0.1 Pout (W) 299.3 235.4 195.5 155.6 115.7 75.8 35.9 23.9 17.2 9.6 6.0 299.3 235.4 195.5 155.6 115.7 75.8 35.9 23.9 17.2 9.6 6.0 299.3 239.4 199.5 159.6 119.7 79.8 40.0 23.9 16.0 12.0 6.0 299.3 239.4 199.5 159.6 119.7 79.8 39.9 efficiency 94% 93% 94% 93% 93% 92% 90% 92% 90% 87% 83% 95% 95% 95% 94% 94% 92% 92% 89% 90% 87% 83% 97% 97% 97% 97% 97% 96% 93% 93% 92% 89% 89% 98% 98% 98% 99% 98% 97% 95% PF 1 1 0.99 0.99 0.99 0.98 0.93 0.85 0.78 0.71 0.65 0.99 0.99 0.99 0.98 0.98 0.95 0.83 0.77 0.73 0.65 0.58 0.98 0.97 0.96 0.94 0.9 0.82 0.66 0.55 0.51 0.47 0.33 0.97 0.96 0.95 0.92 0.88 0.8 0.6 11 17 13.5 6.8 0.14 0.13 0.11 399 399 399 0.04 0.03 0.015 16.0 12.0 6.0 94% 89% 88% 0.49 0.41 0.22 98.0% Efficiency 96.0% 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 Power Factor 0.8 0.7 85V 110V 220V 265V 0.6 0.5 0.4 0.3 0.2 0.1 0 5.6 40 120 200 300 Output Power (W) 12 Harmonic test according to EN61000-3-2 Class D requirement 1. 85VAC, full load (300W output) Iin 2. 85VAC, 9% of full load (28W output) Iin 3. 265VAC, full load (300W output) Iin 13 4. 265VAC, 9% of full load (28W output) Iin Waveforms (soft start, load jump, open loop) 1.Soft start, test at 85VAC, Iout=0.2A Iin Vout Vcc 14 2.Load jump test at 85VAC, Iout from 0A to 0.75A Vout Iout Vgate 3. Load jump test at 85VAC, Iout from 0.75A to 0A Vout Iout Vgate 15 4. Open loop test at 265VAC, Iout=0.1A Vgate Vout Iin Vsense 16 References: [1] Infineon Technologies: ICE1PCS01 - Standalone Power Factor Correction Controller in Continuous Conduction Mode; Preliminary datasheet; Infineon Technologies; Munich; Germany; May 2003. [2] Junyang Luo, Meng Kiat Jeoh, Ming Lik Yew and Heng Cheong Huang, Novel Cost Effective CCM PFC Controller, application note, Infineon Technologies, May 2003. 17