TB429

® Using the EL7515 Demo Board Technical Brief June 7, 2004 TB429 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. 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 2  V O = V FB ×  1 + ------  R 1  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. where VFB is shown in the VFB vs VDD curve. C21 VO4 D21 C14 VO3 D12 C11 VO2 D11 L1 VIN C1 1 PGND 2 SGND R3 R6 R7 5 LBI R8 LBO 6 LBO EN 4 EN SS 7 3 RT LX 10 VDD 9 FB 8 C3 R1 C7 C4 R2 R9 R4 C5 C6 C8 D1 C12 C13 VO1 Q1 L2 VO11 C15 C22 FIGURE 1. COMPLETE SCHEMATIC OF EL7515 DEMO BOARD L1 VIN C1 1 PGND R6 R3 2 SGND 3 RT 4 EN 5 LBI LX 10 VDD 9 FB 8 C3 SS 7 LBO 6 R1 C10 C4 R2 R4 C5 C6 D1 VO1 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 R1 R2 R3 R4 R6 C1 C3 C4 C5 C6 C10 L1 D1 VALUE 10kΩ/1%, 0603 82.5kΩ/1%, 0603 100kΩ, 0603 1kΩ, 0603 0Ω 10µF,16V, 1206 20nF, 0603 0.1µF/16V, 0805 22µF, 16V, 1812 0.1µF/16V, 0805 10nF, 0603 10µH MBR0520 MANUFACTURER Any Any Any Any Any Murata Any Any TDK Any Any Coilcraft On Semiconductor 847-639-6400 800-282-9855 DO1608C-103 MBR0520 C4532X5R1C226M 1-770-436-1300 GRM31CR61106KC31B MANUFACTURER’S PHONE NUMBER MANUFACTURER’S PART NUMBER EL7515 Bill of Materials for VO=18V (Figure 2) FS = 1.2MHz REFERENCE DESIGNATOR R1 R2 R3 R4 R6 C1 C3 C4 C5 C6 C10 L1 D1 VALUE 10kΩ/1%, 0603 124kΩ 47.5kΩ 2.26kΩ 0Ω 10µF, 16V, 1206 20nF, 0603 0.1µF/16V, 0805 22µF, 16V, 1812 0.1µF/16V, 0805 10nF 6.8µH MBR0520 MANUFACTURER Any Any Any Any Any Murata Any Any TDK Any Any Coilcraft On Semiconductor 847-639-6400 800-282-9855 DO1608C-682 MBR0520 C4532X5R1C226M 1-770-436-1300 GRM31CR61106KC31B MANUFACTURER’S PHONE NUMBER MANUFACTURER’S PART NUMBER 2 Technical Brief 429 L1 VIN (2.3V-3.7V) C1 1 PGND 2 SGND R3 R6 R7 5 LBI R8 LBO 6 3 RT 4 EN LX 10 VDD 9 FB 8 D1 R4 R5 Q1 L2 VO11 (4V, 400mA) C5 C6 C4 R2 C3 R1 C10 SS 7 FIGURE 3. EL7515 WITH OUTPUT DISCONNECT Disconnect voltage at: R 7  V IN = 0.22 ×  1 + ------  R 8  EL7515 Bill of Materials for VO=4V (Figure 3) FS = 670kHz REFERENCE DESIGNATOR R1, R5, R8 R2 R3 R4 R6 R7 C1 C3 C4 C5 VALUE 10kΩ/1%, 0603 20kΩ/1%, 0603 100kΩ, 0603 51Ω, 0603 0Ω 56.2kΩ 10µF, 16V, 1206 20nF, 0603 0.1µF/16V, 0805 330µF 100µF 0.1µF/16V, 0805 10nF, 0603 10µH 0Ω MBR0520 IRLML6402 MANUFACTURER Any Any Any Any Any Any Murata Any Any Vishay/Sprague Murata Any Any Coilcraft Any On Semiconductor IR 800-282-9855 MBR0520 IRLML6402 847-639-6400 DO1608C-103 207-324-4140 1-770-436-1300 293D476X-020D20 GRM43SR60J107M***B 1-770-436-1300 GRM31CR61106KC31B MANUFACTURER’S PHONE NUMBER MANUFACTURER’S PART NUMBER C6 C10 L1 L2 D1 Q1 3 Technical Brief 429 D11 D12 VO3 (14.5V) L1 VIN (2.7V4.2V) C1 1 PGND 2 SGND R3 R6 3 RT 4 EN 5 LBI C14 C11 D 1 R4 C13 VO1 (5.1V) C5 C6 C15 LX 10 VDD 9 FB 8 C3 SS 7 LBO 6 R1 C4 R2 C10 FIGURE 4. EL7515 WITH DUAL OUTPUTS EL7515 Bill of Materials (Figure 4) VO1 = 5.1V, VO3 = 14.5V, FS = 670kHz REFERENCE DESIGNATOR R1 R2 R3 R4 R6 C1 C3 C4, C6, C11, C14 C5 C10 C13 C15 L1 D1 D2, D3 VALUE 133kΩ/1% 402kΩ/1% 100kΩ 51Ω 0Ω 10µF, 16V, 1206 20nF 0.1µF/16V 22µF, 10V, 1210 10nF, 0603 1µF 4.7µF 10µH MBR0520 BAT54S MANUFACTURER Any Any Any Any Any Murata Any Any Murata Any Any Panasonic Coilcraft On Semiconductor Vishay/Telefunken 408-945-5660 847-639-6400 800-282-9855 402-563-6866 ECJ-3YF1C4752 DO1608C-103 MBR0520 BAT54S 1-770-436-1300 GRM32ER61A226KA65B 1-770-436-1300 GRM31CR61106KC31B MANUFACTURER’S PHONE NUMBER MANUFACTURER’S PART NUMBER 4 Technical Brief 429 C21 D21 C11 D11 L1 VIN C1 1 PGND 2 SGND R3 R6 3 RT 4 EN 5 LBI LX 10 VDD 9 FB 8 C3 SS 7 LBO 6 R1 C10 C4 R2 R4 C5 C6 D1 VO1 (10V) VO2 (19.5V) C12 VO4 (~9.5V) C22 FIGURE 5. EL7515 FOR TRIPLE OUTPUT EL7515 Triple Output Bill of Materials (Figure 5) VO1 = 10V, VO2 = 19.5V, VO4 = -9.5V REFERENCE DESIGNATOR R1 R2 R3 R4 R6 C1 C3 C4, C6, C11, C21 C5 C10 C12, C22 L1 D1 D11, D21 VALUE 10kΩ/1%, 0603 66.5kΩ/1%, 0603 100kΩ, 0603 51Ω, 0603 0Ω 10µF, 16V, 1206 20nF, 0603 0.1µF/16V, 0805 22µF, 16V, 1812 10nF, 0603 4.7µF, 25V 10µH MBR0520 BAT54S MANUFACTURER Any Any Any Any Any Murata Any Any TDK Any Panasonic Coilcraft On Semiconductor Vishay/Telefunken 408-945-5660 847-639-6400 800-282-9855 402-563-6866 ECJ-3YF1C4752 DO1608C-153 MBR0520 BAT54S C4532X5R1C226M 1-770-436-1300 GRM31CR61106KC31B MANUFACTURER’S PHONE NUMBER MANUFACTURER’S PART NUMBER 5 Technical Brief 429 Typical Performance Curves 1.355 1.35 1.345 VFB 1.34 1.335 1.33 1.325 1.32 5 6 7 8 VDD 9 10 11 12 IDD (mA) 3.6 3.4 3.2 3 2.8 2.6 2.4 2.2 2 650 750 850 950 FS (kHz) 1050 1150 1250 VDD=10V VO=12V-18V FIGURE 6. VFB vs VDD FIGURE 7. IDD vs FS 6 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