STEVAL-ISA077V1 High efficiency synchronous rectifier step-up converter demonstration board based on the L6920DB Data brief Features ■ Up to 5.5 V operating input voltage ■ Internal synchronous rectifier ■ Adjustable output voltage from 1.8 V ■ 3.3 V and 5 V fixed output voltages ■ Low battery voltage detection ■ Reverse battery protection ■ 750 mA input current limit ■ Switching frequency up to 1 MHz ■ RoHS compliant STEVAL-ISA077V1 Description The STEVAL-ISA077V1 demonstration board is based on the L6920DB which is a high efficiency monolithic step-up switching converter IC especially designed for battery powered applications, thanks to its minimum startup of 0.8 V, and a minimum operating voltage of 0.6 V. It requires only three external components to realize the conversion from battery voltage to the selected output voltage. It has a minimum output voltage of 1.8 V, which is enough to supply even the most advanced ASICs and microprocessors. The high switching frequency allows the user to choose small inductors and output capacitors for their designs. Supervisory functions include reference voltage, low battery detection, and shutdown, which are provided with overcurrent protection. November 2010 Doc ID 18237 Rev 1 For further information contact your local STMicroelectronics sales office. 1/4 www.st.com 4 Circuit schematic STEVAL-ISA077V1 1 Circuit schematic Figure 1. Schematic circuit 6"!44 6"!44 ,8 2 .# ,( # & ,") '.$ 6/54 2 .# ,$ '.$ &" # & # .# 2 .# 62%& # N& 6/54 '.$ ??? ,"/ ????? 3($. ??? ,"/ * ????? 3($. * 2.# 2.# !-6 2/4 Doc ID 18237 Rev 1 STEVAL-ISA077V1 2 Revision history Revision history Table 1. Document revision history Date Revision 17-Nov-2010 1 Changes Initial release. Doc ID 18237 Rev 1 3/4 STEVAL-ISA077V1 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. © 2010 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 - Philippines - Singapore - Spain - Sweden - Switzerland - United Kingdom - United States of America www.st.com 4/4 Doc ID 18237 Rev 1