STEVAL-ISA090V1 3.5 A step-down switching regulator based on the L4973 Data brief Features ■ Input voltage range: 8 V to 55 V ■ Output voltage: 5.1 V ± 3% (line, load and thermal) ■ Output ripple: 51 mV ■ Output current range: 1 mA to 3.5 A ■ Max output ripple current: 30% ■ Current limit: 4.5 A ■ Switching frequency: 150 kHz ■ RoHS compliant STEVAL-ISA090V1 Description The STEVAL-ISA090V1 demonstration board provides a platform for evaluation of the L4973, a 3.5 A step-down monolithic power switching regulator operating in continuous mode. Based on the selection of the external components, the device can operate in the entire input voltage range of 8 V < VIN < 55 V. The output voltage is limited by the voltage rating of the output capacitor, so it can be adjusted within the 3.3 V < VOUT < 30 V range through voltage divider R3, R4. The input and output capacitors are capable of sustaining the RMS current within the operating range. April 2011 Doc ID 018689 Rev 1 For further information contact your local STMicroelectronics sales office. 1/4 www.st.com 4 Schematic diagram 1 STEVAL-ISA090V1 Schematic diagram STEVAL-ISA090V1 circuit schematic GND plane signal GND signal GND Figure 1. GAPMSMD00022 2/4 Doc ID 018689 Rev 1 STEVAL-ISA090V1 2 Revision history Revision history Table 1. Document revision history Date Revision 01-Apr-2011 1 Changes Initial release. Doc ID 018689 Rev 1 3/4 STEVAL-ISA090V1 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. © 2011 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 018689 Rev 1