STEVAL-TLL011V1

STEVAL-TLL011V1 Driver for up to 40 white LEDs for mid-sized LCD display backlight based on the STLD41 Data brief Features ■ Boost DC-DC converter ■ Drives up to 40 LEDs (4 strings of 10) with a total current up to 120 mA ■ Input voltage range: 3.0 V to 21 V ■ Output current control ■ 1.8 MHz fixed frequency PWM control ■ PWM input for output current dimming with a frequency range of 25 kHz - 50 kHz ■ 2 A integrated switch ■ Overvoltage protection ■ Chip overtemperature detection and protection ■ Less than 1 µA standby current ■ Soft-start function ■ RoHS compliant Description The STEVAL-TLL011V1 demonstration board demonstrates the performance of the STLD41, a boost converter that operates from 3.0 V to 21 V and which can provide an output voltage as high as 38 V. It can drive up to 40 white LEDs connected in 4 strings of 10 LEDs in series. The total output current capability is 120 mA at an output voltage of 38 V. Regulation is performed by the internal error amplifier which works with the feedback voltage from the sensing resistor. The device can be turned ON/OFF by way of the logic signal connected to the EN pin. The LEDs can be dimmed by applying a PWM signal to the PWM input. May 2012 Doc ID 023189 Rev 2 For further information contact your local STMicroelectronics sales office. 1/4 www.st.com 4 Schematic diagram 1 STEVAL-TLL011V1 Schematic diagram Figure 1. Schematic diagram !-V 2/4 Doc ID 023189 Rev 2 STEVAL-TLL011V1 2 Revision history Revision history Table 1. Document revision history Date Revision Changes 28-May-2012 1 Initial release. 30-May-2012 2 Minor text changes to improve readability Doc ID 023189 Rev 2 3/4 STEVAL-TLL011V1 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 TWO AUTHORIZED ST REPRESENTATIVES, 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. © 2012 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 023189 Rev 2