LED driver delivers flicker-free dimming

Ismini Scouras, Contributing editor -- EDN, February 15, 2011

iWatt Inc. has expanded its family of digital LED driver ICs with a two-stage, power-factor-corrected (PFC), primary-side-regulated, leading- and trailing-edge-dimmable, AC/DC Digital PWM Controller targeting 120V/230VAC offline commercial and industrial LED lighting applications.

Designed for isolated or non-isolated LED drivers used in incandescent replacement lamps including both space-constrained (GU10, MR16) and larger (A, PAR) types, the iW3614 (3W to 15W) incorporates features to assure power efficiency, durability, reduced size and component costs, and flicker-free compatibility with existing wall dimmers worldwide.

Key highlights:

• Isolated AC/DC offline 100 Vac / 230 Vac LED driver
• Up to 15 W output power
• Meets harmonic requirements, high power factor (0.94 typical) without dimmer
• Line frequency ranges from 45 Hz to 66 Hz
• Intelligent wall dimmer detection
• Hybrid dimming scheme
• Wide dimming range from 1% up to 100%
• No visible flicker
• Resonant control to achieve high efficiency, 85% without dimmer
• Temperature compensated LED current
• Small size design
• Primary-side sensing eliminates the need for opto-isolator feedback and simplifies design
• Tight LED current regulation ±5%
• Fast start-up, typically 10 µA start-up current
• Hot-plug LED module support

The chip comes in a low-cost, thermally-enhanced SO-8 package with an exposed pad which allows lower die junction-to-PCB thermal resistance for increased reliability.

Pricing: $1.13 in 1,000-piece quantities.

Availability: Sampling.

Product brief: Click here.

This article originally appeared on EE Times.