Isolated LED-Driver ICs deliver more lighting output power with greater accuracy

May 22, 2014 // By Graham Prophet
Power Integrations' LYTSwitch-2 family of isolated LED drivers delivers up to 12W of accurately controlled output power, reduces component count, and enables simpler, smaller, more reliable LED lighting designs.

LYTSwitch-2 LED-driver ICs use primary-side control, resulting in cost-effective, single-sided PCBs with low component counts. Driver isolation allows the LEDs to be attached directly to a metal heat sink, avoiding an electrically isolating enclosure that is often required for non-isolated drivers. Accurate constant-current (CC) output tolerance across temperature (better than ±5% at both low-line and high-line voltages) reduces the need to over-design systems in order to meet requirements such as the U.S. ENERGY STAR minimum-lumens-delivered specification. Designs using LYTSwitch-2 ICs are also highly efficient – up to 90% in typical applications.

LYTSwitch-2 ICs protect the LED load from surges in line voltage, increasing bulb lifetime in regions where the mains voltage is subject to frequent peaks. The constant-current and constant-voltage (CC/CV) control function maintains a constant voltage on the output of the driver during no-load operation, preventing damage to the output filter or shutting down the driver when being tested or installed with no LED string connected. Transition from CC to CV operation is automatic, depending on the load presented to the driver.

Power Integrations adds that LYTSwitch-2 LED-driver ICs can be used as a platform to create products from 1 W to 12 W, for low-cost bulbs, ballasts, down-lights and tubes. Because of the IC’s stability and closely controlled part-to-part variation, engineers can be confident that their designs will be repeatable and manufacturable with little or no performance variation.

LYTSwitch-2 LED-driver ICs feature over-temperature, over-current and open feedback-loop protection, with design-in support from Power Integrations’ PI Expert design software. Devices are packaged in small, cost-efficient SO-8 packages as well as MSOP and eSIP packages for efficient thermal transfer in higher-power applications. Pricing starts at $0.52 for SO-8 devices (10,000).

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