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

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. LT3519 utilizes True Color PWMTM 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; LT3519-2, offering a 2.2MHz switching frequency, enabling designers to optimize efficiency while minimizing external component size.

Typical Application


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, ie the LT3519IMS, LT3519IMS-1 and LT3519IMS-2, are tested and guaranteed to operate from a -40°C to 125°C operating junction temperature. They are priced at $2.94 each in 1,000-piece quantities.