Product category: Power Supply ICs and Controllers
News Release from: Catalyst Semiconductor | Subject: CAT4201
Edited by the Electronicstalk Editorial Team on 26 July 2007
Convertor is cooler
choice for LED driving
Buck convertor offers a simpler and smaller alternative to linear regulators for driving high-brightness LEDs in step-down applications, eliminating the need for heatsinks
Catalyst Semiconductor has released an innovative buck convertor in a TSOT-23 package optimised for driving high-brightness, 350mA LEDs at up 94% efficiency. The first device in a new family of buck convertors, the CAT4201 incorporates Catalyst's patent-pending switching control algorithm. This new architecture reduces system complexity, improves efficiency and allows an external control resistor to preset a regulated LED current up to 350mA from supplies as high as 24V, to provide better inductor control and eliminate the need for a dedicated heatsink.
This article was originally published on Electronicstalk on 26 July 2007 at 8.00am (UK)
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The CAT4201 buck convertor offers a simpler and significantly smaller alternative to linear regulators for driving high-brightness LEDs in step-down applications, eliminating the need for heatsinks.
Additionally, built-in load dump protection allows transients of 40 volts to be safely handled, fully optimising the CAT4201 for automotive indicator and illumination lighting applications, including turn signal, brake and map reading lights.
Traditionally, LEDs from 12 or 24V buses have been driven by linear regulators, which generate a significant amount of heat, resulting in the need for a dedicated heatsink and, therefore, a very large TO263 package.
The patent-pending switching architecture of the CAT4201 lets designers easily control the average current with a single external resistor.
This results in extremely low internal power dissipation allowing the CAT4201 to be housed in a tiny, 5-lead TSOT-23 package without the need for a dedicated heatsink.
Further reading
LED driver provides precision control
Device drives 16 LEDs directly in parallel and provides LED dimming in 256 brightness steps for backlighting and RGB colour mixing
Two regulators in one save space and cost
Each LDO in the CAT6221 has an independent enable pin and, combined, offer low quiescent current, 1% initial accuracy, and a very low typical dropout voltage
Driver powers up large LED displays
Constant-current sink LED driver is designed for billboard, marquee, instrument and other larger, general-purpose LED displays
Additionally, the device is compatible with switching frequencies up to 1MHz, making it ideal for applications requiring small-footprint, low-cost external inductors.
EZM Lighting, a leading manufacturer of safety lighting for traffic environments has already designed the CAT4201 into its latest tunnel lighting products.
According to Fabiano Paoletto, R and D Manager for EZM Lighting: 'Until now, linear regulators provided an adequate solution for our existing medium-power lighting products'.
'However, as we expanded our product line to include the latest high-power LEDs, driver efficiency and package thermal dissipation issues became critical'.
'The CAT4201 provides a simple yet effective solution, allowing our products to double their lighting power capability without the need for dedicated heatsinking'.
The CAT4201 can drive one 1W LED from a 6V supply or up to seven LEDs in series from a 24V supply.
A dedicated enable control using minimal input current allows the load to be disabled and placed into a zero current shutdown mode, eliminating battery drain when not in use.
Protection against short-circuit and thermal overload fault conditions is also included.
The CAT4201 buck convertor is priced at us $0.72 each in 10,000 piece quantities.
Samples are available now.
Projected lead-time for production quantities is currently 6 to 8 weeks ARO.
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