AC switched matrix technique replaces flyback, buck and boost converters

DALLAS, Nov. 4, 2013 — (PRNewswire) —  Texas Instruments (TI) (NASDAQ: TXN) today introduced the industry's first floating switch architecture that simplifies the offline linear drive of LEDs in lamps, downlights and fixtures. The AC switched matrix technique features TI's TPS92411 floating MOSFET switch and is an innovative approach to producing low-ripple LED drive current without magnetic components. The architecture provides excellent compatibility with legacy wall dimmers and delivers high power factor and low total harmonic distortion (THD). For more information, samples and evaluation modules, visit www.ti.com/tps92411-pr.

Flyback, buck and boost converters are common switch-mode power supply (SMPS) topologies in LED lamps today. These circuits operate at high frequencies and require inductive components to turn mains AC current into the constant DC current necessary to drive LEDs. Selection of inductors and transformers for power transfer is complicated, often requiring expensive custom components. In addition, an electromagnetic interference (EMI) filter consisting of four to ten passive components is required to prevent the SMPS circuit from harming other electronic equipment. If phase dimming is required, multiple design iterations may be necessary to optimize dimmer compatibility and prevent LED flicker.

The floating switch architecture with TI's TPS92411 overcomes these challenges. It requires no inductive components for power transfer, eliminating cost and bulk and simplifying design. Watch a video here.

The TPS92411 joins TI's diverse LED driver portfolio that includes the TPS92075, LM3447 and LM3445.

Key features and benefits of TPS92411:

• 100-V, 2-Ohm floating MOSFET switch with 350 mA of current capability
• LED drive performance is comparable to traditional flyback, buck and boost converters:
  • Greater than 0.95 power factor.
  • Less than 15 percent of total harmonic distortion.
  • Low LED current ripple results in efficient LED utilization as compared with "tapped linear" drivers.
• Low-frequency, slew-rate controlled switch action produces very little EMI noise.
• Unlike designs using traditional converters, the very low-cost floating switch architecture requires no inductive components.
• Works well with both TRIAC and reverse phase wall dimmers.
• Supports lighting designs up to 70 W.

Availability, packaging and pricing
Available now in volume from TI and its authorized distributors, the TPS92411 is offered in a 5-pin SOT-23 package priced at US$0.23 each in 1,000-unit quantities. An evaluation module is offered at $75.00. The TPS92411 in an 8-pin PowerPad™ SOIC package will be available in the first quarter of 2014.

Tools and support:

• Order the TPS92411 light engine evaluation module.
• Download the TPS92411 design calculator tools: 120V or 230V.

Find out more about TI's LED lighting portfolio:

• Get more information on all of TI's lighting products: www.ti.com/lighting-pr.
• Design a complete LED power management system with TI's WEBENCH^® LED Architect.
• Search for solutions, get help and share knowledge in the Power Management forum in the TI E2E™ Community.
• Download an LED reference design from TI's PowerLab™ Reference Design Library.

About TI's LED lighting solutions
From the glow on your smartphone display to brighter headlights, TI's technology drives LEDs in applications to illuminate your path, life and world. Extensive portfolio includes AC/DC, DC/DC, LED drivers, power management devices, wireless and wired interface control and embedded processors for general lighting, signage, backlighting and automotive applications.

About Texas Instruments
Texas Instruments Incorporated (TI) is a global semiconductor design and manufacturing company that develops analog ICs and embedded processors.  By employing the world's brightest minds, TI creates innovations that shape the future of technology.  TI is helping more than 100,000 customers transform the future, today.  Learn more at www.ti.com.

Trademarks
WEBENCH is a registered trademark and PowerPad, TI E2E and PowerLab are trademarks of Texas Instruments. All other trademarks belong to their respective owners.

SOURCE Texas Instruments

Contact:

Texas Instruments Gayle Bullock, Texas Instruments, 408-721-2033 Email Contact Maemalynn Meanor, GolinHarris, 972-341-2564 Email Contact (Please do not publish these numbers or e-mail addresses.) Web: http://www.ti.com