Date: 27/02/2011

Mains power operated LED driver ICs costs 0.7$ each

ST Microelectronics has unveiled new family of mains-operated LED lamp drivers for driving LED lamps inside retrofit lamps featuring primary-side current regulation.

LED lighting, including retrofit bulbs, is expected to account for 80% of the lighting market by 2020 or sooner. Primary-Side Regulation (PSR) cuts bill-of-materials costs for retrofit bulbs, thereby reducing the payback time, while also simplifying design and reducing the space occupied by LED control circuitry.

The new HVLED805 integrates an 800V avalanche-rugged MOSFET, achieved using ST's high-voltage integration process, which is higher than in competing devices and hence offers greater reliability, claims ST. The high-voltage on-chip startup circuitry allows the device to start reliably when the AC line voltage is applied to the lamp.

Primary-side regulation maintains the constant LED current that is needed to ensure consistent light output, without requiring the current-sensing components and opto-coupler used in conventional secondary-side regulation. The elimination of these components decreases the cost and size of the LED driving circuitry and saves current-sensing losses, improving overall efficiency.

Using PSR, the HVLED805 guarantees LED current regulation to within 5% accuracy. Reliability is also enhanced, due to the elimination of the opto-coupler in the secondary side, whose degradation can significantly decrease the mean-time-between-failure of the lamp.

The HVLED805 PSR controller integrates high-voltage startup for efficient power-on, and the robust 800V power MOSFET allows a reduction of the snubber network. The highly efficient quasi-resonant (QR) operating mode further boosts energy savings for LED lighting and dramatically reduces the EMI filtering required, saving space and costs.

Other key specs and features of HVLED805:
800V avalanche-rated MOSFET power switch
5%-accurate constant-current regulation
Quasi-resonant operation
High-voltage startup circuitry
Open- or short-circuit LED string management
Automatic self supply
Input voltage feed-forward for mains-independent constant-current regulation

Package: SO-16N narrow package
Availability: Now in volumes
Price: $0.70 for 10K pieces
Editorial Product Rating: *** (High value) LED driver with integrated MOSFETs withstanding 800V is the need to power LEDs directly. This product is the only such power IC in the market.

For more details visit www.st.com