New LED driver IC for flicker-free TRIAC dimming

PowerIntegrations has announced two single-stage power factor-corrected LED driver ICs for solid-state lighting (SSL) applications that support TRIAC dimming. They are LinkSwitch-PH (suitable for designing isolated power supplies) and LinkSwitch-PL (for designing non-isolated power supplies), both of which enable flicker-free, single-chip TRIAC dimming for illumination similar to incandescent lamps.

Both the LinkSwitch-PH and LinkSwitch-PL product families integrate single-stage power factor correction (PFC) to achieve an SSL lamp with a power factor of 0.9 or higher. The LinkSwitch-PH device uses primary side control technology, eliminating the optocouplers and many auxiliary components commonly used in traditional flyback designs. The non-isolated LinkSwitch-PL design further reduces component count, improving system reliability and reducing bill of materials (BOM). Both device families feature a monolithic design that integrates the controller and MOSFET onto a single die, which reduces component count and eliminates parasitic components between the controller and the power MOSFET, thus greatly simplifying PCB layout. These new LinkSwitch products not only simplify the flyback power supply design, but also increase their efficiency and operate at input voltages up to 305VAC, so they can be used to develop a wide range of residential and commercial lighting applications worldwide. Single voltage products and universal input products.

LEDs are expected to have a lifetime of more than 50,000 hours when operating within the manufacturer's specified temperature and drive current range. The weakest link in LED lighting systems is the driver circuit because it is often subject to unreliable optocouplers and parasitic capacitance. PowerIntegrations' unique precision primary side control technology used in LinkSwitch products eliminates optocouplers. Moreover, the new LinkSwitchLED driver IC product family does not require the use of large parasitic capacitance. Designers using LinkSwitch-PL and LinkSwitch-PH to design SSL products can anticipate that the drive's operating life is comparable to its precise control of the LED array.

BillWeiss, Business Development Manager, PowerIntegrations, said: "These two new product families are ideal for designing space-constrained LED drivers in replacement lamps. The LinkSwitch-PH product line is designed for isolated power supplies with rated output power of up to 50 watts. It is also ideal for designing external LED ballasts commonly used in downlights, architectural lighting, signage, and outdoor lighting. Both of these devices reduce the number and size of BOM components in power systems to increase system reliability. Enables designers to increase system efficiency and meet or exceed all regulatory standards including ENERGY STAR and EN61000-3-2."

Samples of the LinkSwitch-PH device are available now in a halogen-free, ROHS-compliant eSIP-7C package, priced at $1.18 and $1.71 each in 10,000-piece quantities. The LinkSwitch-PLIC will be sampling in August 2010 and will be available in a compact SO-8 and eDIP-12 package.