TRIAC Dimmable LED Driver IC serves retrofit applications.

Press Release Summary:

Flicker-Free™ IS31LT3935 solid state lighting (SSL) LED controller features dimming core based on AccuDim™ technology, which makes LED retrofit lamps have monotonic dimming profile across entire dimming range. With 100% compatibility with leading edge, trailing edge, and digital TRIAC dimmers, single-stage current mode LED controller comes in 3 x 3 mm DFN-10 package with exposed pad and enables 120/230 Vac lamp applications in compact PCB area. Efficiencies are rated up to 87%.

Original Press Release:

ISSI Introduces TRIAC Dimmable LED Driver IC for Retrofit Light Bulbs

AccuDim(TM) Technology Mimics an Incandescent Light Bulb for True Dimming Performance With Near 100% Dimmer Compatibility With a High Power Factor

SAN JOSE, Calif. -- Integrated Silicon Solution, Inc. (Nasdaq:ISSI), a leader in advanced memory and analog IC solutions, has announced the first member of the Flicker-Free™ family of devices, the IS31LT3935. This is ISSI's latest solid state lighting (SSL) LED controller featuring a dimming core based on patent pending AccuDim technology.   AccuDim is an advanced proprietary technique that mimics the characteristics of an incandescent light bulb for true dimming performance with all dimmers maintaining a high power factor. In addition to offering near 100 percent compatibility with leading edge, trailing edge and digital TRIAC dimmers, designs employing the Flicker-Free IS31LT3935 will realize a substantial savings in bill of materials (BOM) cost due to the low component count.

A photo accompanying this release is available at

"Worldwide efficiency regulations are driving consumers to replace standard incandescent lamps with LED-based retrofit lamps," said Ven Shan, ISSI VP of Analog Products. "Unfortunately, the LED retrofit market has exhibited poor performance with the world's installed base of TRIAC or phase-cut dimmers resulting in annoying light flicker. To address this dimmer compatibility problem, AccuDim technology, designed in our Flicker-Free IS31LT3935, makes LED retrofit lamps have a monotonic dimming profile across the entire dimming range as with an incandescent lamp."

The IS31LT3935 is a current mode LED controller that enables 120V/230V AC lamp applications with a high power factor, high efficiency and a low component cost in a small PCB area. Designs using this single stage controller will experience a near unity power factor just like an incandescent lamp yet with very high efficiencies (up to 87%). Other device features include spread-spectrum switching for reduced EMI, safety features such as input over-voltage protection, over-temperature thermal shutdown (with hysteresis) and AC line under voltage lockout. The controller IC feature set enables system designers to exceed all EMI and regulatory standards worldwide.

The IS31LT3935 can be configured as a high-frequency buck mode converter or as a primary side sensing flyback converter. Either mode of operation enables a solution that is both compact and cost effective. Though IS31LT3935 operates over a universal input voltage range (85V to 265V), Flicker-Free reference designs can optimize solutions that are highly efficient and have the lowest BOM by targeting a specific range such as 100V-120V or 220V to 240V AC input voltages up to a 25W power level. Such optimization enables customers to achieve lower overall cost with best in class performance in the smallest form factor to accommodate bulb retrofit designs.

Packaging, Pricing, Availability

The IS31LT3935 is sampling now and will be available in production quantities in Q2 2013. It is available in a small 3x3mm DFN-10 package with exposed pad and is priced at $0.89 in 1,000 piece quantities.

ISSI High Brightness(HB) LED Product Line

ISSI's HBLED product line offers a broad range of Drivers for most types of SSL, including MR-16, GU-10, A-19, PAR Bulbs, Street lamps, Emergency lighting, and Automotive lighting applications. The Flicker-Free product line with AccuDim dimming core offers true TRIAC compatibility. Devices operate from battery voltage, low voltage AC or DC, as well as AC line input voltage. The HBLED product line is geared towards simplifying the application circuit for ease of use, as well as expediting our customer's time to market.

About Integrated Silicon Solution, Inc.

ISSI is a fabless semiconductor company that designs and markets high performance integrated circuits for the following key markets: (i) automotive, (ii) communications, (iii) industrial, medical, and military, and (iv) digital consumer. The Company's primary products are high speed and low power SRAM and low and medium density DRAM. The Company also designs and markets NOR flash products and high performance analog and mixed signal integrated circuits. ISSI is headquartered in Silicon Valley with worldwide offices in Taiwan, Japan, Singapore, China, Europe, Hong Kong, India, and Korea. Visit our web site at

The Integrated Silicon Solution, Inc. logo is available at

CONTACT: Integrated Silicon Solution, Inc.

Ven Shan 408.969.4622

Aaron Reynoso 408.969.5141

Tom Doczy 408-969-4620

Shelton Group

Leanne K. Sievers 949.224.3874

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