White LED Driver delivers 700 mA with over 90% efficiency.
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Press Release Summary:
Inductorless fractional charge pump, Model LTC3215 features multi-mode architecture that automatically switches between 1, 1.5, or 2x boost modes by monitoring voltage across LED current source and switching modes only when ILED dropout is detected. Built-in soft-start circuitry prevents excessive inrush current during start-up. Housed in 3 x 3 mm, 10-lead DFN package, Model LTC3215 offers switching frequency of 900 kHz and is suited for video and flash applications.
Original Press Release:
Inductorless Multi-Mode High Current LED Charge Pump Delivers 700mA of Current with Over 90% Efficiency
Milpitas, CA - March 16, 2005 - Linear Technology Corporation announces the LTC3215, a fractional charge pump, high current white LED driver that delivers up to 700mA of LED current. Its high efficiency multi-mode architecture automatically switches between 1x, 1.5x or 2x boost modes by monitoring the voltage across the LED current source and switching modes only when ILED dropout is detected. This enables the LTC3215 to maximize efficiency (up to 92%) throughout the entire Li-Ion operating range. A 900kHz switching frequency and a low external parts count (two flying capacitors, two programming resistors and two bypass capacitors at VIN and CPO) provide a very tiny footprint and cost-effective solution, ideally suited for video and flash applications in camera phones and other portable lighting applications.
The LTC3215 employs built-in soft-start circuitry which prevents excessive inrush current during start-up. An ultralow dropout current source maintains accurate LED current as the input voltage approaches the LED forward voltage. The LTC3215 is available in a low profile (0.75mm), 3mm x 3mm 10-lead DFN package.
The LTC3215EDD is available from stock in a DFN-10 package. Pricing starts at $1.75 each for 1,000-piece quantities.
Summary of Features: LTC3215
High Efficiency Operation: 1x, 1.5x or 2x Boost Modes with Automatic Mode Switching
Ultralow Dropout ILED Current Control
Output Current up to 700mA
Low Noise Constant Frequency Operation
Tiny Application Circuit (All Components <1mm Profile)
3mm x 3mm 10-Lead DFN Package
Company Background
Linear Technology Corporation was founded in 1981 as a manufacturer of high performance linear integrated circuits. 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, 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.
Call toll-free 1-800-4-LINEAR (for literature only), or go to the company's web site: www.linear.com.
Note: LT and LTC are registered trademarks of Linear Technology Corp.
North America
John Hamburger
Tel: (408) 432-1900 ext. 2419
jhamburger@linear.com
Doug Dickinson
Tel: (408) 432 1900 ext. 2233
ddickinson@linear.com
