Using the EL7515 Demo Board ® Technical Brief June 7, 2004 The complete schematic of EL7515 demo board is shown in Figure 1. With different components stuffed, this demo board can easily be configured into the applications shown in this technical brief. The standard demo board being sent out is the complete 5V to 12V converter shown in Figure 2, which occupies less than 0.4 in2 area with components on top side only. Layout diagrams are given at the end of this document. TB429 3. IO - up to 600mA depending on input voltage, provided that diode and inductor can handle the corresponding currents (refer to data sheet for the chart) 4. Switching frequency - can be set by R3 5. R4 can be 10Ω - 51Ω if VO is less than 10V. If VO is larger than 12V, it can be calculated by: V O – 10 R 4 = -------------------I DD where IDD is a function of switching frequency, as shown in the IDD vs FS curve. 1. VIN = 2V-5.5V. Can be higher with higher voltage rated C1 2. VO = 12V. Can be set according to the following formula: R V O = V FB × 1 + ------2- R 1 where VFB is shown in the VFB vs VDD curve. C21 VO4 D21 C22 C14 VO3 D12 C15 C11 VO2 D11 L1 C12 C13 D1 VO1 Q1 L2 VIN VO11 C1 R4 R3 1 PGND LX 10 2 SGND VDD 9 C6 R2 3 RT FB 8 4 EN SS 7 5 LBI LBO 6 C8 C4 EN R6 C5 C3 R9 R1 C7 R7 LBO R8 FIGURE 1. COMPLETE SCHEMATIC OF EL7515 DEMO BOARD L1 D1 VIN VO1 C1 R4 R6 R3 1 PGND LX 10 2 SGND VDD 9 C5 C6 C4 R2 3 RT FB 8 4 EN SS 7 5 LBI LBO 6 C3 R1 C10 FIGURE 2. 5V TO 12V CONVERTER 1 CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures. 1-888-INTERSIL or 321-724-7143 | Intersil (and design) is a registered trademark of Intersil Americas Inc. Copyright © Intersil Americas Inc. 2004. All Rights Reserved. Elantec is a registered trademark of Elantec Semiconductor, Inc. All other trademarks mentioned are the property of their respective owners. Technical Brief 429 EL7515 Bill of Materials for VO=12V (Figure 2) FS = 670kHz REFERENCE DESIGNATOR VALUE MANUFACTURER MANUFACTURER’S PHONE NUMBER MANUFACTURER’S PART NUMBER R1 10kΩ/1%, 0603 Any R2 82.5kΩ/1%, 0603 Any R3 100kΩ, 0603 Any R4 1kΩ, 0603 Any R6 0Ω Any C1 10µF,16V, 1206 Murata 1-770-436-1300 GRM31CR61106KC31B C3 20nF, 0603 Any C4 0.1µF/16V, 0805 Any C5 22µF, 16V, 1812 TDK C6 0.1µF/16V, 0805 Any C10 10nF, 0603 Any L1 10µH Coilcraft 847-639-6400 DO1608C-103 D1 MBR0520 On Semiconductor 800-282-9855 MBR0520 MANUFACTURER’S PHONE NUMBER MANUFACTURER’S PART NUMBER 1-770-436-1300 GRM31CR61106KC31B C4532X5R1C226M EL7515 Bill of Materials for VO=18V (Figure 2) FS = 1.2MHz REFERENCE DESIGNATOR VALUE MANUFACTURER R1 10kΩ/1%, 0603 Any R2 124kΩ Any R3 47.5kΩ Any R4 2.26kΩ Any R6 0Ω Any C1 10µF, 16V, 1206 Murata C3 20nF, 0603 Any C4 0.1µF/16V, 0805 Any C5 22µF, 16V, 1812 TDK C6 0.1µF/16V, 0805 Any C10 10nF Any L1 6.8µH Coilcraft 847-639-6400 DO1608C-682 D1 MBR0520 On Semiconductor 800-282-9855 MBR0520 2 C4532X5R1C226M Technical Brief 429 L1 VIN (2.3V-3.7V) D1 Q1 C1 R4 R3 1 PGND LX 10 2 SGND VDD 9 C6 VO11 (4V, 400mA) C4 R2 3 RT FB 8 4 EN SS 7 5 LBI LBO 6 C3 R6 C5 R5 L2 R1 C10 R7 R8 FIGURE 3. EL7515 WITH OUTPUT DISCONNECT Disconnect voltage at: R V IN = 0.22 × 1 + ------7- R 8 EL7515 Bill of Materials for VO=4V (Figure 3) FS = 670kHz REFERENCE DESIGNATOR VALUE MANUFACTURER R1, R5, R8 10kΩ/1%, 0603 Any R2 20kΩ/1%, 0603 Any R3 100kΩ, 0603 Any R4 51Ω, 0603 Any R6 0Ω Any R7 56.2kΩ Any C1 10µF, 16V, 1206 Murata C3 20nF, 0603 Any C4 0.1µF/16V, 0805 Any C5 330µF 100µF C6 0.1µF/16V, 0805 Any C10 10nF, 0603 Any L1 10µH Coilcraft L2 0Ω Any D1 MBR0520 On Semiconductor Q1 IRLML6402 IR 3 MANUFACTURER’S PHONE NUMBER MANUFACTURER’S PART NUMBER 1-770-436-1300 GRM31CR61106KC31B Vishay/Sprague 207-324-4140 293D476X-020D20 Murata 1-770-436-1300 GRM43SR60J107M***B 847-639-6400 DO1608C-103 800-282-9855 MBR0520 IRLML6402 Technical Brief 429 D11 D12 VO3 (14.5V) L1 VIN (2.7V4.2V) C14 C11 D 1 C13 C1 R4 R3 1 PGND LX 10 2 SGND VDD 9 C5 C6 C4 R2 3 RT FB 8 4 EN SS 7 5 LBI LBO 6 C3 R6 C15 VO1 (5.1V) R1 C10 FIGURE 4. EL7515 WITH DUAL OUTPUTS EL7515 Bill of Materials (Figure 4) VO1 = 5.1V, VO3 = 14.5V, FS = 670kHz REFERENCE DESIGNATOR VALUE MANUFACTURER MANUFACTURER’S PHONE NUMBER MANUFACTURER’S PART NUMBER R1 133kΩ/1% Any R2 402kΩ/1% Any R3 100kΩ Any R4 51Ω Any R6 0Ω Any C1 10µF, 16V, 1206 Murata 1-770-436-1300 GRM31CR61106KC31B C3 20nF Any C4, C6, C11, C14 0.1µF/16V Any C5 22µF, 10V, 1210 Murata 1-770-436-1300 GRM32ER61A226KA65B C10 10nF, 0603 Any C13 1µF Any C15 4.7µF Panasonic 408-945-5660 ECJ-3YF1C4752 L1 10µH Coilcraft 847-639-6400 DO1608C-103 D1 MBR0520 On Semiconductor 800-282-9855 MBR0520 D2, D3 BAT54S Vishay/Telefunken 402-563-6866 BAT54S 4 Technical Brief 429 C21 VO4 (~9.5V) D21 C22 C11 VO2 (19.5V) D11 L1 C12 D1 VIN C1 VO1 (10V) R4 R3 1 PGND LX 10 2 SGND VDD 9 C5 C4 R2 3 RT FB 8 4 EN SS 7 5 LBI LBO 6 C3 R6 C6 R1 C10 FIGURE 5. EL7515 FOR TRIPLE OUTPUT EL7515 Triple Output Bill of Materials (Figure 5) VO1 = 10V, VO2 = 19.5V, VO4 = -9.5V REFERENCE DESIGNATOR VALUE MANUFACTURER R1 10kΩ/1%, 0603 Any R2 66.5kΩ/1%, 0603 Any R3 100kΩ, 0603 Any R4 51Ω, 0603 Any R6 0Ω Any C1 10µF, 16V, 1206 Murata C3 20nF, 0603 Any C4, C6, C11, C21 0.1µF/16V, 0805 Any C5 22µF, 16V, 1812 TDK C10 10nF, 0603 Any C12, C22 4.7µF, 25V Panasonic 408-945-5660 ECJ-3YF1C4752 L1 10µH Coilcraft 847-639-6400 DO1608C-153 D1 MBR0520 On Semiconductor 800-282-9855 MBR0520 D11, D21 BAT54S Vishay/Telefunken 402-563-6866 BAT54S 5 MANUFACTURER’S PHONE NUMBER MANUFACTURER’S PART NUMBER 1-770-436-1300 GRM31CR61106KC31B C4532X5R1C226M Technical Brief 429 Typical Performance Curves 1.355 3.6 1.35 3.4 3.2 IDD (mA) 1.345 VFB VDD=10V VO=12V-18V 1.34 1.335 1.33 3 2.8 2.6 2.4 1.325 2.2 1.32 5 6 7 8 9 10 VDD FIGURE 6. VFB vs VDD 6 11 12 2 650 750 850 950 1050 FS (kHz) FIGURE 7. IDD vs FS 1150 1250 Technical Brief 429 Demo Board Layout 2000 mil 2000 mil FIGURE 8. TOP LAYER 2 in 2 in FIGURE 9. TOP SILKSCREEN 2000 mil 2000 mil FIGURE 10. BOTTOM LAYER 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 7