Data brief
For further information contact your local STMicroelectronics sales office.
May 2009 Doc ID 15711 Rev 1 1/4
4
STEVAL-ILL027V1
18 W single stage offline LED driver demonstration board
based on the L6562A
Features
■Input voltage 120 VAC +/-10%
■Provides 18 W constant power to HBLED
■Able to drive 14 to 20 HBLED in series
■Soft switching
■LED open circuit protection
■LED short circuit protection
■Power factor > 0.8
■Efficiency > 87%
■RoHS compliant
Description
This demonstration board implements a 18 W
non-isolated soft-switched high power factor
offline LED driver. The buck-boost converter is
chosen for this application due to its simplicity and
low cost. The converter operates with constant
peak current for constant power control and in
transition mode (boundary mode between CCM
and DCM) to achieve soft switching.
High power factor is achieved by reshaping the
peak current nearby the zero crossing of input AC
line.
STEVAL-ILL027V1
www.st.com
Obsolete Product(s) - Obsolete Product(s)
Obsolete Product(s) - Obsolete Product(s)
Obsolete Product(s) - Obsolete Product(s)
Circuit schematic STEVAL-ILL027V1
2/4 Doc ID 15711 Rev 1
1 Circuit schematic
Figure 1. Schematic diagram
AM03804v1
LEDs
R1
R2
Rs
AC +
-
L6562A
ZCD
-
+
Vcc
MULT
INV CS
L1
R4
R3
Q1
LEDs
R1
R2
Rs
AC +
-
L6562A
ZCD
-
+
Vcc
MULT
INV CS
L1
R4
R3
LEDs
R1
R2
Rs
AC +
-
L6562A
ZCD
-
+
Vcc
MULT
INV CS
L1
R4
R3
Q1
Obsolete Product(s) - Obsolete Product(s)
Obsolete Product(s) - Obsolete Product(s)
STEVAL-ILL027V1 Revision history
Doc ID 15711 Rev 1 3/4
2 Revision history
Table 1. Document revision history
Date Revision Changes
18-May-2009 1 Initial release.
Obsolete Product(s) - Obsolete Product(s)
Obsolete Product(s) - Obsolete Product(s)
STEVAL-ILL027V1
4/4 Doc ID 15711 Rev 1
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.
© 2009 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
Obsolete Product(s) - Obsolete Product(s)
