EVAL6725 L6725: 20A Demoboard Data Brief General description L6725 demoboard realizes in a four layer PCB a step-down DC/DC converter and shows the operation of the device in a general purpose application. The input voltage can range from 4.5 V to 14 V and the output voltage is at 3.3 V. The module can deliver an output current in excess of 20 A. The switching frequency is set at 250 KHz (controller free-running FSW) but it can be set to 500 KHz acting on the EAREF pin. Demoboard picture January 2007 Rev 1 For further information contact your local STMicroelectronics sales office. 1/5 www.st.com Features 1 EVAL6725 Features Figure 1. Demoboard schematic VIN D1 C9 R9 C11 J1 C12-C13 C10 R5 VCCDR BOOT GIN R6 J2 EAREF EXT REF 3 8 11 OCH HGATE 5 7 10 12 R8 C7 GND LGATE R10 R12 D3 Q1-3 L6725 15 Q4-6 VOUT 6 U1 VCC C8 L1 PHASE C5 VCC R11 9 2 C16-C19 C15 PGND GOUT SS C4 4 OCL R7 16 1 COMP C2 VFB R3 R4 C3 R1 C1 R2 Table 1. 2/5 Demoboard part list Reference Value Manufacturer Package Supplier R1 1 kΩ Neohm SMD 0603 IFARCAD R2 1 kΩ Neohm SMD 0603 IFARCAD R3 4. 7kΩ R4 2.7 kΩ Neohm SMD 0603 IFARCAD R5 0Ω Neohm SMD 0603 IFARCAD R6 N.C. Neohm SMD 0603 IFARCAD R7 2 kΩ Neohm SMD 0603 IFARCAD R8 10 Ω Neohm SMD 0603 IFARCAD R9 1.5 kΩ Neohm SMD 0603 IFARCAD R10 2.2 Ω Neohm SMD 0603 IFARCAD R11 2.2 Ω Neohm SMD 0603 IFARCAD R12 N.C. Neohm SMD 0603 IFARCAD C1 4.7 nF Kemet SMD 0603 IFARCAD C2 47 nF Kemet SMD 0603 IFARCAD C3 1 nF Kemet SMD 0603 IFARCAD C4 100 nF Kemet SMD 0603 IFARCAD C5 100 nF Kemet SMD 0603 IFARCAD EVAL6725 Features Table 1. Demoboard part list (continued) Reference Value Manufacturer Package Supplier C6 N.C. / / / C7 100 nF Kemet SMD 0603 IFARCAD C8 4.7 µF 20 V AVX SMA6032 IFARCAD C9 1 nF Kemet SMD 0603 IFARCAD C10 1 µF Kemet SMD 0603 IFARCAD C11 220 nF Kemet SMD 0603 IFARCAD C12-13 3X 15 µF / / ST (TDK) C15 N.C. / / / C16-19 2X 330 µF / / ST (poscap) L1 1.8 µH Panasonic SMD ST D1 STPS1L30M ST DO216AA ST D3 N.C. / / / Q1-Q2 STS12NH3LL ST SO8 ST Q4-Q5 STS25NH3LL ST SO8 ST U1 L6725 ST SO16N ST Table 2. Other inductor manufacturer Manufacturer Series Inductor value (µH) Saturation current (A) WURTH ELEKTRONIC 744318180 1.8 20 SUMIDA CDEP134-2R7MC-H 2.7 15 EPCOS HPI_13 T640 1.4 22 TDK SPM12550T-1R0M220 1 22 TOKO FDA1254 2.2 14 HCF1305-1R0 1.15 22 HC5-1R0 1.3 27 Series Capacitor value(µF) Rated voltage (V) C4532X5R1E156M 15 25 C3225X5R0J107M 100 6.3 NIPPON CHEMI-CON 25PS100MJ12 100 25 PANASONIC ECJ4YB0J107M 100 6.3 COILTRONICS Table 3. Other capacitor manufacturer Manufacturer TDK 3/5 Revision history 2 EVAL6725 Figure 2. Demoboard efficiency Figure 3. Demoboard layout Revision history Table 4. 4/5 Revision history Date Revision 03-Jan-2007 1 Changes First issue EVAL6725 Please Read Carefully: Information in this document is provided solely in connection with ST products. STMicroelectronics NV and its subsidiaries (“ST”) reserve the right to make changes, corrections, modifications or improvements, to this document, and the products and services described herein at any time, without notice. All ST products are sold pursuant to ST’s terms and conditions of sale. Purchasers are solely responsible for the choice, selection and use of the ST products and services described herein, and ST assumes no liability whatsoever relating to the choice, selection or use of the ST products and services described herein. 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