Drivers for Ultra-Compact LED Lamps

The first in a new family of mains-operated LED lamp drivers from STMicroelectronics will enable designers to deliver more reliable and efficient LED 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. The high-voltage on-chip startup circuitry allows the device to start reliably when the AC line voltage is applied to the lamp.

Picture: STMicroelectronics

Further technical information:
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.

Major 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

The HVLED805 is in mass production now and available in the SO-16N narrow package.

About these ads
This entry was posted in Uncategorized. Bookmark the permalink.

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s