Power factor corrected AC/DC drivers for LED lighting

December 17, 2014 // By Graham Prophet
ON Semiconductor’s PFC offline AC/DC drivers extend single stage solutions with high power factor capability and broaden two stage solutions up to 150W

NCL30085, NCL30086 and NCL30088 address single stage design implementations up to 60W that require high power factor. The NCL30030 broadens the existing solutions which support higher power (up to 150W) two-stage topologies that require low optical ripple and wide LED forward voltage variation.

ON says that these PFC controllers address the need for higher performance solutions in the LED lamp and driver market, delivering precise current regulation that translates into LED lighting designs that are more flexible and can be future proofed with a common control approach.

The NCL30085, NCL30086 and NCL30088 use a power factor corrected current control algorithm which makes them suitable for flyback buck-boost, and SEPIC topologies. By operating in quasi-resonant mode these devices are able to deliver optimum efficiency across wide line and load levels. The control methodology they employ allows strict current regulation to be achieved (within 2%, typically) solely from the primary side.

The non-dimmable NCL30088 is complemented by the NCL30086, which is 'smart-dimmable', supporting analogue and/or pulse-width modulation (PWM) dimming with a single input that controls the average LED current. Completing the series is the NCL30085 which supports three levels of log step dimming (70, 25 and 5%). It permits light output reduction by toggling the AC switch on/off to signal the controller to lower the LED current point. All three devices feature user-configurable current thermal fold-back mechanisms that help prevent overheating and enable manufacturers to support longer lifetime warranties.

The NCL30085 and NCL30088 are in SOIC-8 packages, while the NCL30086 is in SOIC-10, with pricing of the series starting at $0.35 (10,000).

NCL30030 is a two stage PFC controller plus quasi-resonant flyback controller for medium and high power LED lighting applications up to 150W. This device is best suited for commercial lighting such as lowbay, highbay and streetlighting. The NCL30030 makes use of a proprietary multiplier architecture to achieve low harmonic distortion and near-unity power factor while operating in critical conduction mode