Application Note 1789 ISL8225MEVAL2Z 6-Phase, 90A Evaluation Board Setup Procedure The ISL8225M is a complete, dual step-down switching mode DC/DC module. The dual outputs can easily be paralleled for single-output, high-current use. It is easy to apply this high-power, current-sharing DC/DC power module to power-hungry datacom, telecom, and FPGA applications. All that is needed in order to have a complete, dual 15A design ready for use are the ISL8225M, a few passive components, and VOUT setting resistors. Recommended Equipment The ease of use virtually eliminates design and manufacturing risks while dramatically improving time to market. Need more output current? Simply parallel up to six ISL8225M modules to scale up to an 180A solution. • 100MHz quad-trace oscilloscope The ISL8225M has a thermally enhanced, compact QFN package that operates at full load and over-temperature without requiring forced-air cooling. Easy access to all pins, with few external components, reduces PCB design to a component layer and a simple ground layer. The ISL8225MEVAL2Z evaluation board allows for a single 6-phase paralleled output, which delivers high current up to 90A. The input voltage is 4.5V to 20V and the default output voltage on this board is set at 1.2V. The current level for this board is 90A with no extra cooling required. Related Resources See how-to video at intersil.com/ evid02 + VIN • 0V to 20V power supply with at least 10A source current capability • Electronic load capable of sinking current up to 90A (multiple electronic current loads can be used in parallel to sink more current) • Digital multimeters (DMMs) Quick Start The inputs are J3 (VIN) and J4 (GND). The outputs are J1 and J5 (VOUT), J2 and J6 (GND) and J6 (VOUT2). Please refer to Figure 1. This 90A evaluation board can be easily modified to 30A (one module) or 60A (two modules) operation. 1. Connect a power supply capable of sourcing at least 10A to the input (VIN J3 & GND J4) of the ISL8225MEVAL2Z evaluation board, with a voltage between 4.5V to 20V. Connect an electronic load or the device to be powered to the output (VOUT (J1, J5) & GND (J2, J6)) of the board. All connections, especially the low voltage, high current VOUT lines, should be able to carry the desired load current and should be made as short as possible. Duplicated tab connections on VOUT (J1, J5) and GND (J2, J6) to carry large current. 2. Ensure the jumpers for EN2 and EN3 are in the “ON” position and EN is open. Turn on the power supply. If the board is working properly, the green LED will illuminate; if not, the red LED will illuminate (recheck the wire/jumper connections in this case). Measure the output voltage, VOUT, which should be at 1.2V. 3. The ISL8225MEVAL2Z is manufactured with a VOUT default value of 1.2V; if different output voltages are desired, board resistors can be exchanged to provide the desired VOUT. Please refer to Table 1 on page 2 for R2/R64 resistor values, which can be used to produce different output voltages. + V LOAD (0A~90A) NOTE 1 4.5V TO 20V - - + V VOUT - NOTE: 1. Multiple loads can be paralleled to reach 90A (i.e. Two 45A loads paralleled together). FIGURE 1. ISL8225MEVAL2Z BOARD IMAGE December 3, 2012 AN1789.0 1 CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures. Copyright Intersil Americas Inc. 2012. All Rights Reserved. 1-888-INTERSIL or 1-888-468-3774 | Intersil (and design) is a trademark owned by Intersil Corporation or one of its subsidiaries. All other trademarks mentioned are the property of their respective owners. Application Note 1789 For 12V VIN and VOUT more than 1.5V, the switching frequency will need to be adjusted, as shown in Table 1. The resistor RFSET can be adjusted for the desired frequency. No frequency adjustments are necessary for VOUT below 1.5V. For 5V VIN, the frequency does not need to be adjusted and the module default frequency can be used at any allowed VOUT. If the output voltage is set to more than 1.8V, the output current will need to be derated to allow for safe operation. Please refer to the derating curves in the ISL8225M datasheet. TABLE 1. VALUE OF BOTTOM RESISTOR FOR DIFFERENT OUTPUT VOLTAGES (R1 = 1k) VOUT (V) R2 /R64 (Ω) FREQUENCY (kHz) RFSET (Ω) (VIN = 12V) 0.6 0/0 Default Default 0.8 3010/1500 Default Default 1.0 1500750 Default Default 1.2 1000/500 Default Default 1.5 665/332 Default Default 2.5 316/158 650 249k 3.3 221/110 800 124k 5.0 137/68.1 950 82.5k 5.5 121/60.4 950 82.5k Board Setting If low current applications are needed, this 90A evaluation board can be easily programmed to 30A and 60A use. 30A Application (1 Module) EN -- Open, EN2-- OFF, EN3 -- OFF In this mode, only module 1 is running and modules 2 and 3 are disabled. 60A Application (2 Modules) EN -- Open, EN2-- ON, EN3 -- OFF Or: EN -- Open, EN2-- OFF, EN3 -- ON In this mode, only modules 1 and 2 (or 3) are running and module 3 (or 2) is disabled. 90A Application (3 Modules) EN -- Open, EN2-- ON, EN3 -- ON In this mode, all modules are running. Disable All Modules and Use the EN Pin to Start the Modules EN -- Connected In this mode, all modules are disabled and EN can be used to control all modules to startup. 2 Evaluation Board Information The evaluation board size is 150mm x 130mm. It is a 6-layer board, containing 2-ounce copper on the top and bottom layers and 1-ounce copper on all internal layers. The board can be used as a 90A reference design. Refer to the “Layout” section beginning on page 7. The board is made of FR4 material and all components, including the solder attachment, are lead-free. Current Sharing Check The evaluation board allows the user to measure the current sharing accuracy. Four zero ohm resistors (i.e. R59~R62 for M1 channel 2 in Figure 2) are put serially on each output with two on each side of the evaluation board. To measure the output current of each phase, please remove all four resistors and put looped wires or sensing resistors on correct positions. Although the assembled resistors have zero resistance, there is still small resistance (< 50mΩ) on each resistor. At large output current, the efficiency can be decreased by 1~3% due to the power loss on those zero ohm resistors. The efficiency curves are shown in Figures 16 and 17 with zero ohm resistors, while Figures 18 and 19 show the efficiency curves by replacing those resistors with short copper straps. Thermal Considerations and Current Derating For high current applications, board layout is very critical in order to make the module operate safely and deliver maximum allowable power. To carry large currents, the board layout needs to be designed carefully to maximize thermal performance. To achieve this, select enough trace width, copper weight and the proper connectors. This evaluation board is designed for running 90A @ 1.2V at room temperature without additional cooling systems needed. However, if the output voltage is increased or the board is operated at elevated temperatures, then the available current is derated. Refer to the derated current curves in the datasheet to determine the output current available. For layout of designs using the ISL8225M, the thermal performance can be improved by adhering to the following design tips: 1. Use the top and bottom layers to carry the large current. VOUT1, VOUT2, Phase 1, Phase 2, PGND, VIN1 and VIN2 should have large, solid planes. Place enough thermal vias to connect the power planes in different layers under and around the module. 2. Phase 1 and Phase 2 pads are switching nodes that generate switching noise. Keep these pads under the module. For noise-sensitive applications, it is recommended to keep phase pads only on the top and inner layers of the PCB; do not place phase pads exposed to the outside on the bottom layer of the PCB. To improve the thermal performance, the phase pads can be extended in the inner layer, as shown in Phase 1 and 2 pads on layer 3 (Figure 11) for this 90A evaluation board. Make sure that layer 2 and layer 4 have the GND layers to cover the extended areas of phase pads at layer 3 to avoid noise coupling. AN1789.0 December 3, 2012 Application Note 1789 3. To avoid noise coupling, we recommend adding 1nF capacitors on all COMP and ISHARE pins of each module for multiple module operations. 4. Place the modules evenly on the board and leave enough space between modules. If the board space is limited, try to put the modules with low power loss closely together (i.e. low VOUT or IOUT) while still separating the module with high power loss. 5. If the ambient temperature is high or the board space is limited, airflow is needed to dissipate more heat from the modules. A heat sink can also be applied to the top side of the module to further improve the thermal performance (heat sink recommendation: Aavid Thermalloy, part number 375424B00034G, www.aavid.com). Remote Sensing The ISL8225MEVAL2Z board allows the user to apply the remote sensing function to loads in order to achieve good output regulation accuracy. To make use of this function, remove resistors R7 and R8 and connect the kelvin sensing lines through the jumper JP4 (RS) to the point of load. Phase-shift Programming In current sharing mode, the phase-shift is needed to interleave the different phases to lower the input and output ripples. As shown in Table 2, there are different sharing modes from 2-phase (180° phase-shift) and 4-phase (90° phase-shift) to 6-phase (60° phase-shift). The master module sends the CLKOUT signal to the SYNC pin of the second module with the phase-shift to its own clock signal. Then the second module synchronizes to the CLKOUT signal of the master module and sends its CLKOUT signal to the third module’s SYNC pin. The individual 2 phases of each module are set to be 180° phase-shift by default. This evaluation board is set to mode 5B with 60° phase-shift between phases. If the MODE pin is not tied to VCC (5A or 5B), all VMON pins of different modules can be tied together, except the VMON pin of the master phase. If mode 7A is needed to allow for 90° phase-shift, the MODE pin has to tie to VCC. In this case, the VMON pin of the associated module needs to be separated by connecting a 1.05kΩ resistor to SGND, as shown in the ISL8225M datasheet. TABLE 2. ISL8225M 3-MODULE BOARD OPERATION MODES 1ST MODULE (I = INPUT; O = OUTPUT; I/O = INPUT AND OUTPUT, BI-DIRECTION) MODES OF OPERATION ISHARE (I/O) OPERATION REPRESENTS MODE WHICH OF 2ND VSEN2+ CLKOUT/REFIN CHANNEL(S) 2ND CHANNEL WRT CURRENT (I) WRT 1ST (I OR O) 1ST (O) MODULE OPERATION MODE OF 3RD MODULE OUTPUT MODE EN2 (I) EN3 (I) VSEN2(I) MODE (I) 5A 0 0 VCC GND - 60° Both Channels 180° - - 2-Phase 5B 1 1 VCC GND - 60° Both Channels 180° 5B 5B 6-Phase 7A 1 0 VCC VCC VCC 90° Both Channels 180° 5A or 7A - 4-Phase 8 Cascaded Module Operation MODEs 5A+5A+7A+5A+5A+5A/7A, No External Clock Required 3 12-Phase AN1789.0 December 3, 2012 ISL8225MEVAL2Z Board Schematics C11 C08 IN OPEN C07 330UF 47UF C05 C06 OPEN VOUT VOUT TP9 R40 0 RS - 0 R8 DNP C08A 330UF C04 R7 + 1K E 47UF 0 TP10 OPEN R2 R39 C03 0 1K R53 C02 R1 0 GND E C01 21 0 JP4 OPEN C40 22 R38 OPEN C12 IN J2 0 C35 COMP GND 0.01UF GND_S1 S1 1000PF J6 EGND R13 C6 100PF CLKOUT1 OPEN C10 OUT S1 DNP VMON C29 OUT 1000PF C4 0 R18 C5 1000PF 1K R6 JP8 3 3 4 0 PGOOD OUT DNP R10 PHASE2U1 PHASE1U1 R5 3K S3 R60 1000PF 22UF CIN4 DNP 1 DNP C7 C19 19 20 2 1000PF 22UF CIN3 CIN2 22UF 22UF CIN1 0 R47 VOUT1 18 17 16 VCC1 VOUT ISHARE IN S1 SGND1 E E S1 DRAWN BY: TIM KLEMANN RELEASED BY: UPDATED BY: S1 TIM KLEMANN DATE: ENGINEER: DATE: TITLE: 08/23/2012 JIAN YIN DATE: 11/01/2012 TESTER 2 MASK# E FILENAME: FIGURE 2. ISL8225MEVAL2Z BOARD SCHEMATIC DATE: ISL8225M EVALUATION BOARD SCHEMATIC HRDWR ID ISL8225MEVAL2Z SHEET REV. D Application Note 1789 VOUT2 COMP1 ISHARE VMON1 S3 R61 V1SEN2+ 23 S1 S1 Q1 2N7002-7-F 1 EN 0 0 TP8 VSEN1- CLKOUT 15 R56 COMP2 MODE VMON2 SYNC 470UF CINA 2 3 4 5 EN/FF1 EN/FF2 GRN RED LED1 SSL_LXA3025IGC IN VCC EN/FF OUT R59 VCC1 0 OUT 0 R11 E J5 IN 24 E 3.32K IN 1000PF R62 R9B 25 PGOOD R9 3.32K PGOOD SGND IN R12 6 IN 7 VCC1 VIN1 14 V1SEN2+ S1 C8 VOUT OUT 1 VSEN1+ 13 DNP M1 PHASE1 PGND S1 IN 499 COMP 26 VSEN2+ PHASE2 IN VIN2 ISL8225MIRZ N/C 12 MODE1 R16 8 9 470UF CINB 4 E VCC1 499 S1 VSEN2- 10 11 DNP R82 0 TP4 IN R64 E GND R15 0 TP1 OUT J1 1.2V @ 90A VOUT S1 R42 PGND VCC1 VMON S1 E GND J4 100PF R14 C32 249K OUT IN 0 MODE1 S1 4.7UF S1 1000PF J3 C1 TP6 VIN OUT OUT R10B TP3 TP7 VCC1 OPEN C18 4.5V TO 20V VIN R22 IN IN VIN SYNC IN RFSET SYNC OPEN SYNC TP5 AN1789.0 December 3, 2012 ISL8225MEVAL2Z Board Schematics (Continued) DNP DNP COMP2 C13 100PF CLKOUT2 OPEN S2 C016 330UF OPEN 47UF C015 C013 OPEN C012 OPEN 47UF C011 R87 47UF DNP C0 C42 R86 C010 R70 DNP C47 OPEN E R52 IN 1000PF VMON1 OUT 0 ISHARE S2 DATE: ENGINEER: RELEASED BY: DATE: TITLE: UPDATED BY: DATE: DRAWN BY: OUT OUT OPEN DNP R3 S2 VOUT 0 0 R4 OUT C30 0 C15 S2 OPEN R20 R20B C25 C16 1000PF 0 R19 C17 E R27 0 DNP E R69 OPEN S2 S2 1000PF EGND 0 C37 IN 1000PF PHASE2U2 DNP R57 19 OFF VCC2 R66 VCC2 20 1 R72 PGOOD 21 COMP1 18 17 16 J8 2 S2 GND_S2 15 EN2 ON OUT 0 C36 22UF 22UF CIN8 22UF CIN7 22UF CIN6 PHASE1U2 VOUT1 VMON1 ISHARE CLKOUT EN/FF1 EN/FF2 3 0 R65 22 E EN/FF 0 23 VSEN1- OUT R68 S2 TIM KLEMANN TIM KLEMANN 08/23/2012 11/01/2012 TESTER MASK# FIGURE 3. ISL8225MEVAL2Z BOARD SCHEMATIC DATE: JIAN YIN ISL8225M EVALUATION BOARD SCHEMATIC HRDWR ID REV Application Note 1789 VOUT2 0 COMP2 VMON2 MODE SYNC VCC SGND R49 2 3 4 5 6 VIN1 0 IN R71 V2SEN2+ 24 PGOOD VSEN1+ 14 IN S2 SGND2 25 V2SEN2+ DNP S2 7 PGND 13 IN R17 PHASE1 12 S2 VCC2 ISL8225MIRZ N/C 26 0 0 R28B 1 VSEN2+ M2 PHASE2 10 IN DNP VIN2 VSEN2- 11 MODE2 8 9 E E IN R67 S2 PGND R48 OUT COMP OUT 0 COMP2 IN 5 CIN5 IN R45 S2 0 C09 C26 E IN OUT R43 S2 VMON VMON1 OUT 4.7UF VCC2 R28 DNP MODE2 C2 VIN C14 0 100PF R35 0 C33 R23 0 OPEN OUT R54 1000PF VCC2 OUT OPEN R25 CLKOUT1 AN1789.0 December 3, 2012 ISL8225MEVAL2Z Board Schematics (Continued) OUT C3 R44 S3 C28 S3 C22 OPEN S3 0 R80 330UF OPEN C024 47UF C021 OPEN VOUT OPEN OPEN C017 C019 OUT 47UF C44 R24 E OPEN DNP 0 0 DNP E R81 1000PF C31 C23 DNP OUT 1000PF C27 100PF C20 OUT R79 C018 20 19 18 17 16 15 14 13 1000PF R37 R29 0 ISHARE OUT S3 DATE: ENGINEER: RELEASED BY: DATE: TITLE: UPDATED BY: DATE: DRAWN BY: CLKOUT3 0 R76 0 OPEN 21 IN S3 S3 E 22 VMON2 S3 C24 EGND C39 COMP3 1000PF 3 0 2 J7 R26 1 0 PGOOD S3 TP11 GND_S3 OUT R37B PHASE2U3 PHASE1U3 DNP OPEN C9 OUT OFF EN3 S3 24 COMP1 EN/FF ON R78 VCC3 0 IN C023 2 3 4 5 6 7 8 9 22UF 22UF CIN12 22UF CIN11 22UF CIN10 DNP R51 VOUT1 IN 0 S3 TIM KLEMANN TIM KLEMANN 08/23/2012 11/01/2012 TESTER MASK# FIGURE 4. ISL8225MEVAL2Z BOARD SCHEMATIC DATE: JIAN YIN ISL8225M EVALUATION BOARD SCHEMATIC HRDWR ID REV. Application Note 1789 VOUT2 VMON1 CLKOUT3 R74 V3SEN2+ IN E S3 CLKOUT3 R77 23 VSEN1- ISHARE CLKOUT R58 COMP2 MODE VMON2 SYNC EN/FF1 EN/FF2 IN TP2 0 R75 VSEN1+ VIN1 26 VCC3 V3SEN2+ DNP VCC PHASE1 R21 R73 R44B 1 25 ISL8225MIRZ PGOOD N/C S3 IN VSEN2+ M3 PGND VCC3 SGND 10 12 IN VIN2 PHASE2 MODE3 DNP IN 0 VSEN2- 11 IN OUT E E R50 COMP2 0 S3 PGND VCC3 R46 IN 6 CIN9 IN OUT S3 1000PF VIN IN VMON2 COMP3 0 E VMON1 C014 4.7UF R31 OUT MODE3 DNP 0 C21 R36 0 100PF R33 0 DNP R55 C34 VCC3 OUT OPEN R30 CLKOUT2 AN1789.0 December 3, 2012 Application Note 1789 Layout OFF ON FIGURE 5. TOP ASSEMBLY FIGURE 6. TOP SILK SCREEN FIGURE 7. TOP LAYER COMPONENT SIDE FIGURE 8. LAYER 2 7 AN1789.0 December 3, 2012 Application Note 1789 Layout (Continued) FIGURE 9. LAYER 3 FIGURE 10. LAYER 4 FIGURE 11. LAYER 5 FIGURE 12. BOTTOM LAYER SOLDER SIDE 8 AN1789.0 December 3, 2012 Application Note 1789 Layout (Continued) FIGURE 13. BOTTOM SILK SCREEN FIGURE 14. BOTTOM SILK SCREEN MIRRORED FIGURE 15. BOTTOM ASSEMBLY 9 AN1789.0 December 3, 2012 Bill of Materials PART NUMBER REF DES QTY. VALUE TOL. VOLTAGE POWER 10TPB330M C04, C08, C016, C024, C08A 5 330µF 20% 131-4353-00 TP1 2N7002-7-F JEDEC TYPE MANUFACTURER DESCRIPTION 10 CAP_7343_149 SANYO-POSCAP Standard solid electrolytic chip tantalum SMD capacitor 1 CONN TEK131-4353-00 Tektronix Scope probe test point PCB mount Q1 1 SOT23 SOT23 Fairchild N-Channel EMF effect transistor (Pb-free) 5002 TP2-TP11 10 THOLE MTP500X Keystone Miniature white test point 0.100 pad 0.040 Thole ECA-1VM471 CINA, CINB 2 470µF 20% 35V RADIAL CAPR_708X1398_300_P Panasonic Radial capacitor Pb-free C1-C3 3 4.7µF 10% 16V 805 CAP_0805 Murata Ceramic capacitor C0, C02, C05, C010, C013, C014, C018 7 47µF 10% 10V 1210 CAP_1210 Murata Ceramic chip capacitor CIN1-CIN12 12 22µF 10% 25V 1210 CAP_1210 Murata Ceramic chip capacitor H1045-00101-50V10 C6, C7, C13, C14, C20, C21 6 100pF 10% 50V 603 CAP_0603 Generic Multilayer capacitor H1045-00102-16V10 C8 1 1000pF 10% 16V 603 CAP_0603 Generic Multilayer capacitor H1045-00102-50V10 C4, C5, C9, C11, C16-C19, C23-C31, C40 18 1000pF 10% 50V 603 CAP_0603 Generic Multilayer capacitor H1045-00103-50V10 C35 1 0.01µF 10% 50V 603 CAP_0603 Generic Multilayer capacitor H1045-OPEN C10, C12, C15, C22, C32-C34, C36, C37, C39, C42, C44, C47 13 OPEN 5% OPEN 603 CAP_0603 Generic Multilayer capacitor H1082-OPEN C01, C03, C06, C07, C09, C011, C012, C015, C017, C019, C021, C023 12 OPEN 10% OPEN 1210 CAP_1210 Generic Ceramic chip capacitor R3, R4, R13-R17, R20, R21,R24, R25, R28-R31, R37, R48, R50, R51, R56-R58, R86, R87, R10B, RFSET 26 DNP 1% 603 RES_0603 Generic Metal film chip resistor (do not populate) GRM32ER70A476K GRM32ER71E226KE15L H2505-DNP-DNP-1 DNP Application Note 1789 SMD GRM21BR71C475KA73L 10V PACKAGE TYPE AN1789.0 December 3, 2012 Bill of Materials (Continued) PART NUMBER H2511-00R00-1/16W1 R7-R10, R18, R19, R22, R23, R26, R27, R33, R35, R36, R42-R47, R49, R52, R54, R55, R81, R9B, R20B, R28B, R37B, R44B 29 0Ω 1% 1/16W 603 RES_0603 Generic Thick film chip resistor H2511-01001-1/16W1 R1, R2, R6 3 1kΩ 1% 1/16W 603 RES_0603 Generic Thick film chip resistor H2511-03321-1/16W1 R11, R12 2 3.32kΩ 1% 1/16W 603 RES_0603 Generic Thick film chip resistor H2511-04990-1/16W1 R64, R82 2 499Ω 1% 1/16W 603 RES_0603 Generic Thick film chip resistor H2520-00R00-1/2W5 R38-R40, R53, R59-R62, R65-R80 24 0Ω 5% 1/2W 2010 RES_2010 Generic Thick film chip resistor ISL8225MIRZ M1-M3 3 QFN QFN26_670X670_ISL8225M Intersil Dual 15A DC/DC power module JUMPER-3-100 J7, J8 2 THOLE JUMPER-3 Generic Three pin jumper JUMPER2_100 JP4, JP8 2 THOLE JUMPER-1 Generic Two pin jumper J1-J6 6 CONN KPA8CTP Burndy Wire connector lug R5 1 603 RES_0603 ROHM Metal film chip resistor LED1 1 SMD LED_3X2_5MM Lumex 3mmx2.5mm surface mount red/green LED MCR03EZPFX3001 SSL-LXA3025IGC 3kΩ 1% 1/10W JEDEC TYPE MANUFACTURER DESCRIPTION NOTE: 2. Resistance accuracy of the feedback resistor divider R1/R2 can affect the output voltage accuracy. Please use high accuracy resistance (i.e. 0.5% or 0.1%) to meet the output accuracy requirement. Application Note 1789 VALUE 11 QTY. KPA8CTP TOL. VOLTAGE POWER PACKAGE TYPE REF DES AN1789.0 December 3, 2012 Application Note 1789 ISL8225MEVAL2Z Efficiency Curves Test conditions at +25°C and no air flow. Efficiency Curves with Zero-ohm Resistance on the Output 95 3.3VOUT 100 2.5VOUT 90 1.5VOUT EFFICIENCY (%) EFFICIENCY (%) 85 1.2VOUT 75 1VOUT 65 55 3.3VOUT 2.5VOUT 1.2VOUT 1.5VOUT 1VOUT 80 70 0 10 20 30 40 50 60 70 80 90 60 100 0 10 20 30 LOAD CURRENT (A) 40 50 60 70 80 90 100 LOAD CURRENT (A) FIGURE 16. EFFICIENCY CURVES FOR 12V INPUT FIGURE 17. EFFICIENCY CURVES FOR 5V INPUT Efficiency Curves by Replacing Zero-ohm Resistance with Thick Copper Strap 95 3.3VOUT 100 2.5VOUT 90 1.5VOUT EFFICIENCY (%) EFFICIENCY (%) 85 1.2VOUT 75 1VOUT 1.2VOUT 1.5VOUT 1VOUT 80 70 65 55 2.5VOUT 0 10 20 30 40 50 60 70 80 90 LOAD CURRENT (A) FIGURE 18. EFFICIENCY CURVES FOR 12V INPUT 100 60 0 10 20 30 40 50 60 70 80 90 100 LOAD CURRENT (A) FIGURE 19. EFFICIENCY CURVES FOR 5V INPUT Intersil Corporation reserves the right to make changes in circuit design, software and/or specifications at any time without notice. Accordingly, the reader is cautioned to verify that the Application Note or Technical Brief is current before proceeding. For information regarding Intersil Corporation and its products, see www.intersil.com 12 AN1789.0 December 3, 2012