Products, Materials + Tools | Jan 25, 2011

Maxim’s LED Solution Enables Drop-in Replacements for Halogen MR16 Lamps

Maxim Integrated Products introduces the MAX16840, an LED driver that employs a proprietary architecture to ensure flicker-free, dimmable operation with electronic transformers and cut-angle dimmers. Maxim’s patent-pending approach enables the design of retrofit LED lamps that can replace halogen MR16s without any changes to the existing electrical infrastructure. This removes an important obstacle to commercial viability, allowing end users to enjoy all the benefits of LED lighting with substantially lower deployment costs.

To facilitate adoption, LED retrofit lamps must be compatible with electronic transformers and cut-angle dimmers. These transformers and dimmers are designed for the perfectly resistive loads of traditional halogen lamps. LED drivers, however, are very nonlinear and not purely resistive loads. As a consequence, LED lamps flicker, do not dim, and in some cases do not turn on at all when used with the existing electrical infrastructure.

The MAX16840 solves this problem by using a unique, patent-pending approach to control the input current of the lamp. By actively shaping the input current it ensures flicker-free operation with most electronic transformers and dimmers. This enables LED lamp designers to create drop-in replacements for halogen MR16s, thus eliminating the costly infrastructural upgrades required by competitive solutions.

Extending lamp lifetime and fitting the MR16 form factor
In addition, the MAX16840 can be designed in without electrolytic capacitors. This extends the lifetime of the LED lamp, since electrolytic capacitors are usually the first component that fails in the driver circuit.

Operation without electrolytic capacitors reduces the cost and size of the driver, allowing it to fit in the small MR16 form factor. An integrated switching MOSFET further extends these space savings while reducing component count and cost.

Features:
• Control of the average input current to achieve operation with electronic transformers and dimmability
• Buck, boost, SEPIC, and buck-boost topologies
• Integrated 0.2 Ohm (max) 48V switching MOSFET
• Analog dimming and thermal foldback
• External npn driver to guarantee minimum load to electronic transformer at startup
• Output overvoltage protection
• Internal overtemperature protection
• -40°C to +125°C operating temperature range
• 3mm x 3mm, 10-Pin TDFN package

The MAX16840 can deliver up to 20W of power in a thermally enhanced, 3mm x 3mm, 10-pin TDFN package. Prices start at $2.01 (1000-up, FOB USA). For more information, please visit: www.maxim-ic.com/Flicker-Free-LEDs.

About Maxim Integrated Products:
Maxim Integrated Products is a publicly traded company that designs, manufactures, and sells high-performance semiconductor products. The Company was founded over 25 years ago with the mission to deliver innovative analog and mixed-signal engineering solutions that add value to its customers' products. To date, it has developed over 6400 products serving the industrial, communications, consumer, and computing markets.

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