EVAL6902D L6902D 1A Constant current battery charger evaluation board Data Brief General description The L6902D evaluation board integrates the stepdown switching regulator with adjustable current limit L6902D as well as the external components required for a typical application. The input voltage of the application board can range from 8V up to 25V due to the rated voltage of the input capacitor and the schottky rectifier repetitive peak reverse voltage (both 25V). The external resistor divider (R1 and R2) sets the output voltage of the application board to 3.3V. A different output voltage can be regulated from 1.235V up to 10V, which is the rated voltage of the output capacitor. Evaluation board A current limit of 1A is programmed by the 100mΩ sense resistor Rsense. The inductor saturation current and the forward current of the schottky rectifier fit the current limit setting. October 2006 Rev 1 For further information contact your local STMicroelectronics sales office. 1/4 www.st.com 4 EVAL6902D Figure 1. Application test circuit VIN VREF COMP L1 OUT VCC VOUT Rsense D1 CS+ L6902D R1 CSC4 C1 C2 FB C3 R3 Figure 2. Package Table 1. Demoboard part list Name Value P/N Manufacturer C1 10µF C4532X5R1E106M TDK C2 100µF 10TPB100M POSCAP STPS2L25U ST DO1813HC-223 COILCRAFT L6902D ST D1 L1 22µH Device 2/4 R2 GND Notes R1 8.2 kΩ 0603, 1% R2 3.3 kΩ 0603, 1% R3 4.7 kΩ 0603, 1% C3 220pF 0603, 50V C4 22nF 0603, 50V Rsense 100mΩ EVAL6902D 1 Revision history Revision history Table 2. Revision history Date Revision 17-Oct-2006 1 Changes First issue 3/4 EVAL6902D 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. No license, express or implied, by estoppel or otherwise, to any intellectual property rights is granted under this document. If any part of this document refers to any third party products or services it shall not be deemed a license grant by ST for the use of such third party products or services, or any intellectual property contained therein or considered as a warranty covering the use in any manner whatsoever of such third party products or services or any intellectual property contained therein. UNLESS OTHERWISE SET FORTH IN ST’S TERMS AND CONDITIONS OF SALE ST DISCLAIMS ANY EXPRESS OR IMPLIED WARRANTY WITH RESPECT TO THE USE AND/OR SALE OF ST PRODUCTS INCLUDING WITHOUT LIMITATION IMPLIED WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE (AND THEIR EQUIVALENTS UNDER THE LAWS OF ANY JURISDICTION), OR INFRINGEMENT OF ANY PATENT, COPYRIGHT OR OTHER INTELLECTUAL PROPERTY RIGHT. UNLESS EXPRESSLY APPROVED IN WRITING BY AN AUTHORIZED ST REPRESENTATIVE, ST PRODUCTS ARE NOT RECOMMENDED, AUTHORIZED OR WARRANTED FOR USE IN MILITARY, AIR CRAFT, SPACE, LIFE SAVING, OR LIFE SUSTAINING APPLICATIONS, NOR IN PRODUCTS OR SYSTEMS WHERE FAILURE OR MALFUNCTION MAY RESULT IN PERSONAL INJURY, DEATH, OR SEVERE PROPERTY OR ENVIRONMENTAL DAMAGE. ST PRODUCTS WHICH ARE NOT SPECIFIED AS "AUTOMOTIVE GRADE" MAY ONLY BE USED IN AUTOMOTIVE APPLICATIONS AT USER’S OWN RISK. Resale of ST products with provisions different from the statements and/or technical features set forth in this document shall immediately void any warranty granted by ST for the ST product or service described herein and shall not create or extend in any manner whatsoever, any liability of ST. ST and the ST logo are trademarks or registered trademarks of ST in various countries. Information in this document supersedes and replaces all information previously supplied. The ST logo is a registered trademark of STMicroelectronics. All other names are the property of their respective owners. © 2006 STMicroelectronics - All rights reserved STMicroelectronics group of companies Australia - Belgium - Brazil - Canada - China - Czech Republic - Finland - France - Germany - Hong Kong - India - Israel - Italy - Japan Malaysia - Malta - Morocco - Singapore - Spain - Sweden - Switzerland - United Kingdom - United States of America www.st.com 4/4