Date: 08/07/2010

DC/DC converter from Linear drives up to 30 LEDs

Linear has unveiled the LT3596, a 60V, 1MHz step-down DC/DC converter designed to operate as a constant current LED driver for up to 30 LEDs.

The key features of the LT3596 are:
1. This converter can drive up to three strings of LEDs, each with up to ten 100mA LEDs in series from a 48V input and delivers an efficiencies of over 90%.
2. It has multichannel capability and is therefore suggested for LED billboards as well as industrial and medical displays.
3. The converter has an input voltage range of 6V to 60V and is thus suggested for automotive and industrial applications.
4. The LT3596 offers + 1.5% LED current matching for uniform display brightness and True Color PWM dimming can offer dimming ratios as high as 10,000:1.
5. Implements a programmable 200kHz to 1MHz fixed frequency operation and current-mode architecture that ensures stable operation over a wide range of supply and output voltages.
6. The switching frequency is synchronizable to an external clock.
7. Uses a single 800mA, 60V internal switch to provide a step-down constant current source.
8. The internal buck converter uses an adaptive feedback loop to regulate the output voltage slightly higher than the required LED voltage to ensure high efficiency.
9. If any of the LED strings experience an open or short-circuit, it will continue to regulate the other strings and signal the FAULT pin.
10. Other features of LT3596 include LED current derating based on junction temperature and/or LED temperature and LED disconnect in shutdown.

Package:
The LT3596EUHG come in a 39-lead 5mm x 8mm QFN package.

Price:
The LT3596EUHG starts at each US$3.65 for 1,000-piece quantities.
An industrial grade version, the LT3596IUHG is priced at each US$4.29 for 1,000-piece quantities.

For more information visit: www.linear.com/pr/3596