REFERENCE DESIGN IRDCiP2021C-1 International Rectifier 233 Kansas Street, El Segundo, CA 90245 USA IRDCiP2021C-1: 500kHz, 40A, Single Output, Dual Phase Synchronous Buck Converter Featuring iP2021C and IR3623M Overview This reference design is capable of delivering a continuous current of 40A, single output without heatsink at an ambient temperature of 45C and airflow of 200LFM. Fig. 4 - Fig. 16 provide performance graphs, thermal images, and waveforms. Fig. 1 - Fig. 3 are provided to engineers as design references for implementing an IR3623+iP2021C solution. The components installed on this demoboard were selected based on operation at an input voltage of 12V (+/-10%), a switching frequency of 500kHz (+/15%), and an output voltage of 1.2V. Major changes from these set points may require optimizing the control loop and/or adjusting the values of input/output filters in order to meet the user's specific application requirements. Refer to iP2021C and IR3623 datasheets for more information. IRDCiP2021C-1 Recommended Operating Conditions (refer to the iP2021C datasheet for maximum operating conditions) Input voltage: 8.5V - 14.5V Output voltage: 0.8 - 5V Switching Freq: 500kHz Output current: This reference design is capable of delivering a continuous current of 40A without heatsink at an ambient temperature of 45C and airflow of 200LFM. Demoboard Quick Start Guide Initial Settings: VOUT is set to 1.2V, but can be adjusted from 0.8V to 5V by changing the values of R11 and R15 according to the following formula: R11 = R15 = (10k * 0.8) / (VOUT - 0.8) The switching frequency is set to 500kHz, but can be adjusted by changing the value of R26. See Fig. 4 for the relationship between R26 and the switching frequency. 8/13/2009 IRDCiP2021C-1 Power Up Procedure: 1. Apply input voltage across VIN and PGND. 2. Apply load across VOUT pads and PGND pads. 3. Toggle the SEQ (SW1) and EN (SW2) switches to the ON position. 4. Adjust load to desired level. See recommendations above. www.irf.com 2 A B C TP13 SS1 C33 0.1uF TP18 TRACK2 VOUT1 R25 30.1K C31 1uF B1 BOARD C34 open R2 10K R1 10K R4 0 5 30 FLT RT 1 8 17 SS2 26 SS1 25 27 2 1 3 22 VP2 VREF PGD2 VOUT3 PGD1 VOUT3 TRK2 VOUT3 TRK1 VOUT3 SYNC 23 24 SEQ SW2 SEQ 31 12 EN R24 10K VCC R26 78.7K (500kHz) 59.0K (600kHz) 16.2K (1MHz) TP24 FAULT R47 open TP16 PGOOD2 TP15 PGOOD1 TP17 TRACK1 R3 0 SW1 EN R23 10K TP23 SYNC TP14 SS2 C32 100pF R22 open R21 open C13 0.1uF R35 0 TP8 PGND RT FAULT SS2 SS1 VP2 VP1 VREF PGOOD2 PGOOD1 TRACK2 TRACK1 SYNC SEQ ENABLE VCC U3 IRU3623M open R45 13 VOUT3 VIN 32 5V _SNS VOUT3 OCSET2 PWM2 Ph_En2 VSEN2 FB2 COMP2 OCSET1 PWM1 Ph_En1 VSEN1 FB1 COMP1 2 18 TP19 CC1 R5 FB1 11K 9 OC2 PH_EN2 PWM2_IC 10 C42 open VSEN2 open R6 11 4 FB2 6 TP26 FB2 CC2 7 TP20 CC2 OC1 PWM1_IC 14 16 PH_EN1 C41 100pF VSEN1 TP25 FB1 15 21 19 CC1 R15 20K C35 5.6pF C37 2700pF TP9 EN1 R7 200 R16 0 open R36 R32 R28 C36 open 9.31K R46 R31 R27 0 0 TP11 PWM1 TP12 PWM2 TP10 EN2 C57 1000pF C38 open 0 0 R14 R12 R10 R8 R13 R11 R9 open open open open 10K 20K 10K C45 1uF 3 PWM2 EN2 C40 open PWM1 EN1 VDD C39 390pF R19 0 TP31 VO2A R34 10K TP32 VO2B R20 open R33 10K C43 1uF TP30 VO1B TP29 VO1A 6 10 5 11 TP1 +VINS1 VIN C3 10uF 16V C4 10uF 16V C2 10uF 16V C54 1uF C1 10uF 16V C53 1uF 4 9 U1 iP2021 C52 100pF -VOUTS1 TP4 -VOUTS1 PWM2 ENA2 PWM1 ENA1 CVC C +VINS2 TP27 12 TP6 8 2 C5 10uF 16V 3.65K R18 C44 open -VOUTS2 -VOUTS2 VSW2 VSW1 VIN 1 VIN1 PGND 3 VIN2 PGND 7 D GND 28 PGND 29 PGND 0 OCGn d 20 VDD 4 C46 220uF R30 1.62K C51 100pF 0 R40 VOUT1 C50 0.47uF 0 R39 C8 10uF 16V C49 0.47uF C47 open 0.22uH L2 0.22uH L1 C7 10uF 16V R29 1.62K R17 3.65K TP22 VSW2 VSW2 OC1 VSW1 TP21 VSW1 C6 10uF 16V C48 open FB2 TP5 C16 100uF +VOUTS1 TP3 C17 10uF C11 10uF 16V C58 open C12 10uF 16V C20 100uF C59 220uF R42 0 C19 100uF 5 C22 10uF R43 0 C21 10uF VOS1+ VOS1- C60 open R37 VOUT2 C24 open R44 0 C23 open 0 R49 open R48 0 R38 open C61 open C26 open C25 open 5 Date: 22-Jul-2009 Size: Tabloid Time: 12:38:39 Number: B Sheet 1 of 1 Revision: C62 1uF VOS1S- VOS1S+ Title: iP2021 & IR3623M Eval - Single Output C18 10uF VOUT2 R41 0 VOUT1 C10 10uF 16V C15 100uF +VOUTS2 VOUT2 VP2 VOUT1 C9 10uF 16V 1 2 4 1 2 3 1 2 TP7 VDD 2 1 2 1 2 1 2 1 2 1 3 2 1 6 C14 680uF VIN C56 open TP36 VOUT2 TP2 C55 open TP35 VOUT1 TP37 TP38 PGND PGND PGND TP34 C30 open 1.2V VOS2- PGND TP28 VIN PGND TP33 C29 open International Rectifier 233Kansas St. iPOWIR Group El Segundo CA 90245 C28 open C27 open 1.2V VOS1D- VOS1D+ 6 T9 PGND T6 PGND T4 VOUT2 T2 PGND T1 VIN T7 PGND T5 PGND T3 VOUT1 A B C D IRDCiP2021C-1 Demoboard Schematic Fig. 1 Schematic www.irf.com www.irf.com 4 1 1 20 18 2 1 1 1 2 1 4 1 1 1 2 11 2 1 4 6 4 1 1 1 2 2 1 2 8 2 16 Quantity Designator C1, C2, C3, C4, C5, C6, C7, C8, C9, C10, C11, C12, C17, C18, C21, C22 C13, C33 C14 C15, C16, C19, C20 C31, C43, C45, C53, C54, C62 C32, C41, C51, C52 C35 C37 C39 C46, C59 C49, C50 C57 L1, L2 R1, R2, R9, R13, R23, R24, R33, R34 R11, R15 R3, R4, R16, R27, R28, R31, R32, R38, R39, R40, R49 R17, R18 R19 R25 R26 R29, R30 R35 R41, R42, R43, R44 R46 R5 R7 SW1, SW2 TP1, TP2, TP3, TP4, TP5, TP6, TP7, TP8, TP27, TP28, TP29, TP30, TP31, TP32, TP33, TP34, TP35, TP36 TP9, TP10, TP11, TP12, TP13, TP14, TP15, TP16, TP17, TP18, TP19, TP20, TP21, TP22, TP23, TP24, TP25, TP26, TP37, TP38 U1 U3 X7R LGA unit PWM controller test point hardware iP2021 IC analog test point thick film thick film thick film thick film thick film thick film manganin-foil thick film thick film thick film slide thick film hardware resistor resistor resistor resistor resistor resistor resistor resistor resistor resistor switch resistor capacitor X7R capacitor electrolytic capacitor X5R capacitor X7R capacitor NPO capacitor NPO capacitor X7R capacitor NPO capacitor tantalum polymer capacitor X7R capacitor X7R inductor ferrite resistor thick film resistor thick film T ype 2 Type 1 capacitor rev a -0.5 - 16V 60 mils 90 mils 3.65K 0 30.1K 78.7K 1.62K 0 0 9.31K 11.0K 200 SPDT 0 0.100uF 680uF 100uF 1.00uF 100pF 5.60pF 2700pF 390pF 220uF 0.470uF 1000pF 0.22uH 10.0K 20.0K 10.0uF Value 1 -0.5 - 16V 40 x 105 mils 112 x 150 mils 1/10W 1/8W 1/10W 1/10W 1/10W 1/8W 2W 1/10W 1/10W 1/10W 30VDC 1/10W 50V 16V 6.3V 16V 50V 50V 50V 50V 2.5V 16V 50V 47A 1/10W 1/10W 16V Value 2 5015 5016 0603 0805 0603 0603 0603 1206 2817 0603 0603 0603 pcb mount 0603 0603 SMD 1210 0603 0603 0603 0603 0603 7343 0603 0603 SMT 0603 0603 1206 Package 7.65mm x 11mm -40 - 120C MLPQ-32L - - 1% <50m 1% 1% 1% <50m n/a 1% 1% 1% 0.2A 1% 10% 20% 20% 10% 5% +/-0.50pF 10% 5% 20% 10% 10% 10% 1% 1% 10% Tolerance IRF IRF Keystone Keystone KOA ROHM KOA KOA KOA Panasonic Isotek Corp KOA KOA KOA E-Switch KOA TDK Panasonic TDK TDK Phycomp KOA KOA KOA Sanyo TDK BC Component Vitec KOA KOA TDK Manufac 1 Manufac 1No rev a IR3623M 5015 5016 RK73H1JLTD3651F MCR10EZHJ000 RK73H1J3012F RK73H1JLTD7872F RK73H1JLTD1621F ERJ-8GEY0R00 SMT-R000 RK73H1JLTD9311F RK73H1JLTD1102F RK73H1J2000F EG1218 RK73Z1JLTD C1608X7R1H104K EEV-FK1C681GP C3225X5R0J107M C1608X7R1C105KT 0603CG101J9B20 NPO0603HTTD5R6D X7R0603HTTD272K NPO0603HTTD391J 2R5TPC220M C1608X7R1C474KT 0603B102K500NT 59PR9873N RK73H1J1002F RK73H1J2002F C3216X7R1C106KT IRDCiP2021C-1 Bill of Material IRDCiP2021C-1 Demoboard Component Placement Fig. 2 Top Layer (Face View) Fig. 3 Bottom Layer (Through View) 5 www.irf.com IRDCiP2021C-1 Description of Test Points and Connectors 1. Jumpers Jumper SW1 SW2 2. Pin Name EN SEQ Description Board Enable ( switch Up = Off, Down = On ) - Vin pin on top Sequence ( switch Up = Off, Down = On ) - Vin pin on top Test Points/Connectors Test Point Pin Name Description T1 / T2 VIN / PGND Vin supply voltage TP2 / TP28 VIN / PGND Vin supply voltage sense T3 / T5 / T7 VOUT1 / PGND / PGND Channel 1 Output, connect to DC load TP35 / TP33 VOUT1 / PGND Channel 1 Output sense TP21 / TP37 VSW1 / PGND Channel 1 switch node / PGND test points TP9 EN1 Channel 1 Enable test point TP11 PWM1 Channel 1 PWM test point TP19 CC1 Channel 1 error amplifier output TP25 FB1 Channel 1 error amplifier non-inverting input T4 / T6 / T9 VOUT2 / PGND / PGND Channel 2 Output, connect to DC load TP36 / TP34 VOUT2 / PGND Channel 2 Output sense TP22 / TP38 VSW2 / PGND Channel 2 switch node / PGND test points TP10 EN2 Channel 2 Enable test point TP12 PWM2 Channel 2 PWM test point TP20 CC2 Channel 2 error amplifier output TP26 FB2 Channel 2 error amplifier non-inverting input VDD / PGND Supply voltage for IRU3623 and iPOWIR module TP23 SYNC External frequency synchronization input TP17 TRACK1 Channel 1 tracking input, pull-up to Vout3 if not used TP18 TRACK2 Track2 test point TP15 PGOOD1 Channel 1 Power good test point TP16 PGOOD2 Channel 2 Power good test point TP13 SS1 Channel 1 Soft start test point TP14 SS2 Channel 2 Soft start test point TP24 FAULT Fault monitor test point TP7 / TP8 3. Test points for Efficiency Measurement Test Point Pin Name Description TP1 / TP4 +VINS1 / -VOUTS1 Channel 1 Vin sense for efficiency measurement TP3 / TP4 +VOUTS1 / -VOUTS1 Channel 1 Output sense for efficiency measurement TP27 / TP6 +VINS2 / -VOUTS2 Channel 2 Vin sense for efficiency measurement TP5 / TP6 +VOUTS2 / -VOUTS2 Channel 2 Output sense for efficiency measurement www.irf.com 6 IRDCiP2021C-1 Test Results Fig. 4 Relationship Between Switching Frequency and R26 VIN = 12V, VOUT = 1.2V, Iout = 40A, fsw = 500 kHz Fig. 5 Power Up Sequence (C3: EN, C1: SS1, C4: VOUT) VIN = 12V, VOUT = 1.2V, Iout = 40A, fsw = 500 kHz Fig. 6 Power Down Sequence (C3: EN, C1: SS1, C4: VOUT) 7 www.irf.com IRDCiP2021C-1 VIN = 12V, VOUT = 1.2V, fsw = 500 kHz Fig. 7 Hiccup Mode Over Current Protection (C1: SS1, C4: Iout, C3: VOUT) VIN = 12V, VOUT = 1.2V, fsw = 500 kHz Fig. 8 Hiccup Mode Over Current Protection (C1: SS1, C4: Iout, C3: VOUT) Fig. 9 Deadtime and Ringing on Switch Node www.irf.com 8 IRDCiP2021C-1 VIN = 12V, VOUT = 1.2V, Iout = 20A, fsw = 500 kHz Vp-p = 20 mV Fig. 10 Output Voltage DC Ripple VIN = 12V, VOUT = 1.2V, Iout = 20A, fsw = 500 kHz Fig. 11 Output Voltage DC Ripple VIN = 12V, VOUT = 1.2V, Iout = 0-40A, 0.5A/s, fsw = 500 kHz Fig. 12 Load Transient Response (C1: VOUT - AC, C2: Iout divided by 2) 9 www.irf.com IRDCiP2021C-1 fc = 65 kHz PM = 49 Fig. 13 Bode Plot (VIN = 12V, VOUT = 1.2V, Iout = 20A) Current Sharing Accuracy The accuracy of current sharing is tested by measuring the DC voltage across the two inductors at the following operating conditions: VIN = 12V; VOUT = 1.2V; Iout = 10 - 40A. The test results are shown below: Table 1 Inductor DC Voltages at Different Currents for Single Output Configuration Iout (A) 10 20 30 40 www.irf.com VL1 (mV) 1.5 3.4 5.5 7.5 10 VL2 (mV) 1.9 3.8 5.8 7.9 IRDCiP2021C-1 VIN = 12V, VOUT = 1.2V, 200LFM, fsw = 500kHz, No Heatsink 6.0 45C Room Temperature 5.5 Power Loss (W) 5.0 4.5 4.0 3.5 3.0 2.5 2.0 1.5 1.0 0 5 10 15 20 25 30 35 40 Load Current (A) Fig. 14 Power Loss VIN = 12V, VOUT = 1.2V, 200LFM, fsw = 500kHz, No Heatsink 92% 90% 88% Efficiency 86% 84% 82% 80% 78% 76% 45C 74% Room Temperature 72% 0 5 10 15 20 25 30 35 40 Load Current (A) Fig. 15 Efficiency 11 www.irf.com IRDCiP2021C-1 Fig. 16 Thermal Image: Iout = 40A, VIN = 12V, VOUT = 1.2V, TA = 45oC, fsw = 500kHz, 200LFM, No Heatsink, Maximum IC Temperature = 94.2oC Refer to the following application notes for detailed guidelines and suggestions when implementing iPOWIR Technology products: AN-1043: Stabilize the Buck Converter with Transconductance Amplifier This paper explains how to design the voltage compensation network for Buck Converters with Transconductance Amplifier. The design methods and equations for Type II and Type III compensation are given. AN-1028: Recommended Design, Integration and Rework Guidelines for International Rectifier's iPowIR Technology BGA and LGA and Packages This paper discusses optimization of the layout design for mounting iPowIR BGA and LGA packages on printed circuit boards, accounting for thermal and electrical performance and assembly considerations. Topics discussed include PCB layout placement, and via interconnect suggestions, as well as soldering, pick and place, reflow, inspection, cleaning and reworking recommendations. AN-1030: Applying iPOWIR Products in Your Thermal Environment This paper explains how to use the Power Loss and SOA curves in the data sheet to validate if the operating conditions and thermal environment are within the Safe Operating Area of the iPOWIR product. AN-1047: Graphical solution for two branch heatsinking Safe Operating Area Detailed explanation of the dual axis SOA graph and how it is derived. Use of this design for any application should be fully verified by the customer. International Rectifier cannot guarantee suitability for your applications, and is not liable for any result of usage for such applications including, without limitation, personal or property damage or violation of third party intellectual property rights. IR WORLD HEADQUARTERS: 233 Kansas St., El Segundo, California 90245, USA Tel: (310) 252-7105 TAC Fax: (310) 252-7903 www.irf.com 12