CAT4026 6-Channel LED Controller with Fault Diagnostics for Large Panel LED Backlighting http://onsemi.com Description The CAT4026 is a high performance, large panel LED controller designed to control six constant current high voltage LED strings. Added control circuitry monitors the lowest cathode voltage and generates a feedback control signal to an external Switch Mode Power Supply (SMPS) to provide a low cost and efficient solution for large panel high voltage LED backlighting. Each LED channel current is accurately matched and controlled by sensing an external resistor in series with a low cost bipolar power transistor. This allows current and heat dissipation concerns to be mitigated from the CAT4026 device package. For added system reliability, both Open−Cathode−Anode (OCA) and Shorted−Cathode−Anode (SCA) fault detection circuitry has been included along with independent Fault flag logic outputs for diagnostic purposes. LED current dimming in all six channels can be precisely controlled by either a Pulse Width Modulation signal via the PWM input pin or by an analog dimming voltage applied at the ANLG pin. In addition the ANLG pin provides a convenient method for limiting the overall maximum power dissipation in the event of excessive LED shorting within any LED string. The device will automatically enter low current shutdown mode by taking the PWM pin low for an extended length of time. PIN CONNECTIONS VDD PWM ANLG BASE1 RSET1 BASE2 RSET2 BASE3 RSET3 OCA C1 N.C. VA N.C. 1 GND SCA VCS BASE6 RSET6 BASE5 RSET5 BASE4 RSET4 FLT−OCA C3 FLT−SCA IFB VC (Top View) MARKING DIAGRAM Features • • • • • • • • • • SOIC−28 V SUFFIX CASE 751BM 6 Channel LED Controller Adaptive Feedback Control to External SMPS for Better Efficiency PWM and Analog Mode Dimming Short Cathode−Anode (SCA) Fault Protection Open Cathode−Anode (OCA) Fault Protection Over−Voltage Protection Thermal Shutdown Protection Automatic Inactivity Power Down Mode SOIC−28L Package These Devices are Pb−Free, Halogen Free/BFR Free and are RoHS Compliant Typical Applications L3A CAT4026V YYWWXXXX L = Assembly Location Code 3 = Mark “3” for (lead finish Matte−Tin) A = Product Revision: Fixed as “A” CAT4026V = Specific Device Code YY = Production Year (Last Two Digits) WW = Production Week (Two Digits) XXXX = Last Four Digits of Assembly Lot Number ORDERING INFORMATION • LCD−TV LED Backlighting • LED General Lighting Device CAT4026V−T1 (Note 1) Package Shipping SOIC−28 (Pb−Free) 1,000/ Tape & Reel 1. Matte Tin Plated Finish (RoHS−compliant) © Semiconductor Components Industries, LLC, 2010 February, 2010 − Rev. 2 1 Publication Order Number: CAT4026/D CAT4026 Example of Ordering Information (Note 4) 2. 3. 4. 5. 6. Prefix Device # Suffix CAT 4026 V − T1 Company ID (Optional) Product Number 4026 Package V: SOIC−28L Lead Finish Blank: Matte Tin Tape & Reel (Note 6) T: Tape & Reel 1: 1,000 / Reel All packages are RoHS−compliant (Lead−free, Halogen−free). The standard lead finish is Matte Tin. The device used in the above example is a CAT4026V−T1 (SOIC−28L, Matte Tin, Tape & Reel, 1,000/Reel). For additional package and temperature options, please contact your nearest ON Semiconductor Sales office. For information on tape and reel specifications, including part orientation and tape sizes, please refer to our Tape and Reel Packaging Specifications Brochure, BRD8011/D. ON Semiconductor and are registered trademarks of Semiconductor Components Industries, LLC (SCILLC). SCILLC reserves the right to make changes without further notice to any products herein. SCILLC makes no warranty, representation or guarantee regarding the suitability of its products for any particular purpose, nor does SCILLC assume any liability arising out of the application or use of any product or circuit, and specifically disclaims any and all liability, including without limitation special, consequential or incidental damages. “Typical” parameters which may be provided in SCILLC data sheets and/or specifications can and do vary in different applications and actual performance may vary over time. All operating parameters, including “Typicals” must be validated for each customer application by customer’s technical experts. SCILLC does not convey any license under its patent rights nor the rights of others. SCILLC products are not designed, intended, or authorized for use as components in systems intended for surgical implant into the body, or other applications intended to support or sustain life, or for any other application in which the failure of the SCILLC product could create a situation where personal injury or death may occur. Should Buyer purchase or use SCILLC products for any such unintended or unauthorized application, Buyer shall indemnify and hold SCILLC and its officers, employees, subsidiaries, affiliates, and distributors harmless against all claims, costs, damages, and expenses, and reasonable attorney fees arising out of, directly or indirectly, any claim of personal injury or death associated with such unintended or unauthorized use, even if such claim alleges that SCILLC was negligent regarding the design or manufacture of the part. SCILLC is an Equal Opportunity/Affirmative Action Employer. This literature is subject to all applicable copyright laws and is not for resale in any manner. PUBLICATION ORDERING INFORMATION LITERATURE FULFILLMENT: Literature Distribution Center for ON Semiconductor P.O. Box 5163, Denver, Colorado 80217 USA Phone: 303−675−2175 or 800−344−3860 Toll Free USA/Canada Fax: 303−675−2176 or 800−344−3867 Toll Free USA/Canada Email: [email protected] N. American Technical Support: 800−282−9855 Toll Free USA/Canada Europe, Middle East and Africa Technical Support: Phone: 421 33 790 2910 Japan Customer Focus Center Phone: 81−3−5773−3850 http://onsemi.com 2 ON Semiconductor Website: www.onsemi.com Order Literature: http://www.onsemi.com/orderlit For additional information, please contact your local Sales Representative CAT4026/D