ISSI intros TRIAC dimmable LED driver IC for retrofit light bulbs

USA: Integrated Silicon Solution Inc. 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.

The IS31LT3935 is a current mode LED controller that enables the 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 percent).

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.

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.