DC/DC Converter drives high-current LEDs.

Press Release Summary:




Featuring 3-40 V input voltage range, LT3519, 45 V current sense DC/DC converter drives up to ten 100 mA white LEDs from 12 V input. It senses output current at high side of LED, enabling buck, buck-boost, or boost configurations. True Color PWM(TM) dimming delivers constant LED color with ranges of more than 3,000:1. Providing open LED protection, soft-start, and thermal protection, it is available in switching frequency options of 400 kHz, 1 MHz, and 2.2 MHz.



Original Press Release:



45 V, 750 mA LED Driver for Boost, Buck or Buck-Boost High Current LED Applications



MILPITAS, CA - September 16, 2009 - Linear Technology announces the LT3519, a 45V, high side current sense DC/DC converter designed to drive high current LEDs. The LT3519's 3V to 40V input voltage range makes it ideal for applications such as automotive and industrial lighting. The combination of an internal 45V, 750mA switch, Schottky diode and internal compensation provides a highly compact LED driver solution.

The LT3519 can drive up to ten 100mA white LEDs from a 12V input, making it ideal for a variety of applications such as automotive and industrial lighting. It can deliver efficiencies up to 90% in boost mode from a compact MSOP-16E package. The LT3519 utilizes True Color PWM(TM) dimming to deliver constant LED color with ranges of more than 3,000:1. For less demanding dimming requirements, the CTRL pin can be used to offer 10:1 analog dimming. The device's fixed frequency, constant current, constant voltage regulation provides stable operation over a wide range of supply and output voltages, while ensuring uniform brightness of LEDs. There are three switching frequency options available: the LT3519, which switches at 400kHz; the LT3519-1, which switches at 1MHz; and the LT3519-2, offering a 2.2MHz switching frequency, enabling designers to optimize efficiency while minimizing external component size.

The LT3519 senses output current at the high side of the LED, enabling buck, buck-boost or boost configurations. Combining a traditional voltage feedback and unique floating current sense feedback, these converters can operate as constant voltage or constant current source, offering maximum design flexibility. Other features include open LED protection, soft-start and thermal protection.

The LT3519EMS, LT3519EMS-1 and LT3519EMS-2 are available in an MSOP-16 package and are priced starting at $2.50 each, in 1,000-piece quantities. Extended temperature versions, or "I" grades, namely the LT3519IMS, LT3519IMS-1 and LT3519IMS-2, are tested and guaranteed to operate from a -40ºC to 125ºC operating junction temperature. They are priced at $2.94 each in 1,000-piece quantities. All versions are available from stock. For more information, visit www.linear.com.

Summary of Features: LT3519

Up to 3000:1 True Color PWM(TM) Dimming

3V to 40V Input Voltage Range

Floating LED Current Sense from 0V to 45V

45V, 750mA Internal Switch

Internal Schottky Diode

Constant Current & Constant Voltage Regulation

Boost, SEPIC, Buck-Boost Mode or Buck Mode Topology

Open LED Protection & Open LED Status Pin

Programmable Undervoltage Lockout with Hysteresis

Fixed Frequency: 400kHz (LT3519), 1MHz
(LT3519-1) or 2.2MHz (LT3519-2)

Internal Compensation

CTRL Pin Provides Analog Dimming

Low Shutdown Current: <1µA

16-Lead MSOP Package

750mA, 45V Monolithic LED Driver with 3000:1 True Color PWM Dimming

About Linear Technology

Linear Technology Corporation, a manufacturer of high performance linear integrated circuits, was founded in 1981, became a public company in 1986 and joined the S&P 500 index of major public companies in 2000. Linear Technology products include high performance amplifiers, comparators, voltage references, monolithic filters, linear regulators, DC-DC converters, battery chargers, data converters, communications interface circuits, RF signal conditioning circuits, µModule® products, and many other analog functions. Applications for Linear Technology's high performance circuits include telecommunications, cellular telephones, networking products such as optical switches, notebook and desktop computers, computer peripherals, video/multimedia, industrial instrumentation, security monitoring devices, high-end consumer products such as digital cameras and MP3 players, complex medical devices, automotive electronics, factory automation, process control, and military and space systems.
LT, LTC, LTM, µModule and are registered trademarks of Linear Technology Corp. All other trademarks are the property of their respective owners.

Worldwide Contacts

North America and General Information

John Hamburger

Tel: (408) 432-1900 ext. 2419

jhamburger@linear.com

Doug Dickinson

Tel: (408) 432 1900 ext. 2233

ddickinson@linear.com

China (PRC)

Fanny Lau

Tel: 852-2428-0303

flau@linear.com

Angela Ao

Tel: (8610)6522 8081

angela.ao@ebacomms.com

Japan

Yoshikazu Funasaki

Tel: 81-3-5226-7291

yfunasaki@linear.com

All Topics