IRDCIP2001-B

REFERENCE DESIGN International Rectifier IRDCiP2001-B • 233 Kansas Street, El Segundo, CA 90245 USA Overview IRDCiP2001-B, 500kHz, 60A, 3-phase Synchronous Buck Converter using iP2001 In this document, table 1 and figure 1 are provided to enable engineers to easily evaluate the iP2001 in a 3-phase configuration that is capable of providing up to 60A in a lab environment without airflow. Figures 3, 4, 5 and 6 and the complete bill of materials in table 2 are provided as a reference design to enable engineers to very quickly and easily design a 3-phase converter. In order to optimize this design to your specific requirements refer to the data sheet for the controller listed in the bill of materials. A variety of other controllers may also be used, but the design will require layout and control circuit modifications. Demoboard Quick Start Guide Initial Settings: The output is set to 1.7V, but can be adjusted from 1.1 to 1.85V by setting S1 according to the VID codes provided in Table 1. Droop control is set to 50mV at 60A, but can be adjusted by following the instructions in the data sheet for the PWM controller. The switching frequency per phase is set to 500kHz with the frequency set resistor R4. This creates an effective output frequency of 1.5MHz. The graph in figure 1 shows the relationship between R4 and the switching frequency per phase. This frequency may be adjusted by changing R4 according to this graph; however, extreme changes from the 500kHz set point may require redesigning the control loop and adjusting the values of input and output capacitors. Also, refer to the SOA graph in the iP2001 datasheet for maximum operating current at different frequencies. Procedure for Connecting and Powering Up Demoboard: 1. Apply input voltage (5-12V) across VIN (TP18) and PGND (TP14). Note that this input source must be applied first during the power-up sequence. 2. Apply +5V logic power across +5V (TP19) and PGND (TP20). 3. Apply load across VOUT pads (TP10 - TP12) and PGND pads (TP14 - TP16) 4. Set ENABLE high. 5. Monitor switch node signals (optional) via TP6 - TP8. 6. Adjust load accordingly. iP2001 Recommended Operating Conditions (refer to the iP2001 datasheet for maximum operating conditions) Input voltage: 5 - 12V Output voltage: 1.1 - 1.85V Output current: 20A per phase, 60A total for 3-phase demo board. Switching Freq: 500kHz per phase, 1.5MHz effective output frequency. 07/19/02 IRDCiP2001-B 1000 100 Resistance (kΩ ) 10 1 100 1000 Output Frequency (kHz) Figure 1 - R4 vs. Frequency per Phase VID4 VID3 VID2 VID1 VID0 1 1 1 1 1 1 1 1 1 0 1 1 1 0 1 1 1 1 0 0 1 1 0 1 1 1 1 0 1 0 1 1 0 0 1 1 1 0 0 0 1 0 1 1 1 1 0 1 1 0 1 0 1 0 1 1 0 1 0 0 1 0 0 1 1 1 0 0 1 0 1 0 0 0 1 1 0 0 0 0 2 VDAC Off 1.100 1.250 1.150 1.175 1.200 1.225 1.250 1.275 1.300 1.325 1.350 1.375 1.400 1.425 1.450 VID4 VID3 VID2 VID1 VID0 0 1 1 1 1 0 1 1 1 0 0 1 1 0 1 0 1 1 0 0 0 1 0 1 1 0 1 0 1 0 0 1 0 0 1 0 1 0 0 0 0 0 1 1 1 0 0 1 1 0 0 0 1 0 1 0 0 1 0 0 0 0 0 1 1 0 0 0 1 0 0 0 0 0 1 0 0 0 0 0 VDAC 1.475 1.500 1.525 1.550 1.575 1.600 1.625 1.650 1.675 1.700 1.725 1.750 1.775 1.800 1.825 1.850 www.irf.com Table 1 - PWM IC Voltage Identification Codes IRDCiP2001-B 92% 90% 88% 86% VIN = 12V VOUT = 1.6V TA = 25°C fSW= 1MHz 84% 82% 80% 0 10 20 30 40 50 60 Output Current (A) Figure 2 - Typical Efficiency vs. Current Refer to the following application notes for detailed guidelines and suggestions when implementing iPOWIR Technology products: AN-1028: Recommended Design, Integration and Rework Guidelines for International Rectifier’s iPOWIR Technology BGA Packages This paper discusses the assembly considerations that need to be taken when mounting iPOWIR BGA’s on printed circuit boards. This includes soldering, pick and place, reflow, inspection, cleaning and reworking recommendations. AN-1029: Optimizing a PCB Layout for an iPOWIR Technology Design This paper describes how to optimize the PCB layout design for both thermal and electrical performance. This includes placement, routing, and via interconnect suggestions. 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. www.irf.com Efficiency 3 fSW = 500kHz 12 11 9 10 8 7 1 2 3 4 5 6 7 6 COMP VOUT SENSE TP5 19 PGOOD PWM1 0 VIN C6 10uF SWNODE2 ENABLE PRDY PGND VSW2 C7 10uF C8 10uF C31 10uF 13 SGND R11 0 PWM2 ENABLE R16 10K 14 ISEN2 PWM2 15 VDD Vin VID4 VID3 VID2 VID1 VID0 FS/DIS GND VDD VIN C9 10uF SWNODE3 ENABLE PRDY C27 10uF * 10 VSEN ISEN1 R10 +5V U3 IP2001 16 VID4 PGOOD 1 2 3 4 ISEN3 PWM3 ISEN4 PWM4 HIP6311 SGND PWM3 ENABLE VSW3 PGND +5V R17 10K 18 U4 C10 10uF C11 10uF +5V +5V IP2001 17 Vin C32 10uF 11 R12 0 5 8 R4 51K 9 12 VID3 VID2 VID1 VID0 FB 4 IRDCiP2001-B S1 *Rx &Cx are not parts of PCB R3 open +5V IP2001 VDD C28 22pF R1 1k 0.022uF ENABLE 0.54uH PRDY VCC 20 C2 10uF PGND C16 Open VSW1 0 R14 R15 10K L1 ENABLE SWNODE1 C1 PWM1 +5V SGND C3 10uF C4 10uF C5 10uF C30 10uF R5 2K 1% TP6 SWNODE1 VIN Vin U2 TP18 Vin Rx Cx 51 4700pF ENABLE R6 10K U1 1K R2 VOUT +5V C17 100uF R7 2K 1% TP7 SWNODE2 L2 0.54uH C19 100uF C20 100uF TP10 VOUT TP11 VOUT TP12 VOUT TP13 VOUT VOUT SENSENE TP21 C33 VOUT SENSE 0.01uF X7R PGNDSENSE TP22 PGND SENSE R8 2K 1% TP8 SWNODE3 L3 0.54uH C22 Open C23 100uF Fig. 3 - Reference Design Schematic Note: Rx and Cx are add on components Freq. Set Resistor +5V TP19 TP14 PGND TP15 PGND TP16 PGND TP17 PGND PGND TP20 www.irf.com IRDCiP2001-B Fig. 4 - Component Placement Top Layer Fig. 5 - Component Placement Bottom Layer www.irf.com 5 IRDCiP2001-B Designator C1 C2 - C11, C27, C30 - C32 C16, C22, D1 - D3, R3, R19 C17, C19, C20, C23 C28 C33 Cx L1 - L3 R1, R2 R10 - R12, R14 R6, R15 - R17 R4 R5, R7, R8 Rx S1 ST1 - ST4 U1 U2 - U4 Value 1 0.022uF 10.0uF 100uF 22.0pF 0.010uF 4700pF 0.54uH 1K 0 10K 51K 2K 51 SPST 4-40 Value 2 50V 16V 6.3V 50V 50V 50V 27A 1/8W 1/8W 1/8W 1/8W 1/8W 1/10W 6 position T yp e X7R X5R X5R COG X7R X7R Ferrite Thick film Thick film Thick film Thick film Thick film Thick film Switch PWM controller DC-DC Tolerance 10% 10% 10% 5% 10% 10% 20% 5%