LED Charge Pump delivers 1 A current with 92% efficiency.
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Press Release Summary:
Housed in 3 x 4 x .75 mm, 12-lead DFN package, LTC3216 fractional charge pump has multi-mode architecture that automatically switches between 1X, 1.5X, or 2X boost modes. White LED driver has 900 kHz switching frequency and built-in soft-start circuitry. Independent high and low current settings for flash and torch/video modes are programmed by 2 external resistors, and shutdown mode and current output levels are selected via 2 logic inputs.
Original Press Release:
Inductorless Multi-Mode High Current LED Charge Pump Delivers 1A of Current with Over 90% Efficiency
Milpitas, CA - December 1, 2004 - Linear Technology Corporation announces the LTC3216, a fractional charge pump, high current white LED driver that delivers up to 1A 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 LTC3216 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 tiny footprint ideally suited for video and flash applications in camera phone and other portable lighting applications.
The LTC3216 employs built-in soft-start circuitry which prevents excessive inrush current during start-up. Independent high and low current settings for flash and torch/video modes respectively are programmed by two external resistors. Shutdown mode and current output levels are selected via two logic inputs. An ultralow dropout current source maintains accurate LED current as the input voltage approaches the LED forward voltage. The LTC3216 is available in a low profile (0.75mm), 3mm x 4mm 12-lead DFN package.
The LTC3216EDE is available from stock in a DFN-12 package. Pricing starts at $2.00 each for 1,000-piece quantities.
Summary of Features: LTC3216
High Efficiency Operation: 1X, 1.5X or 2X Boost Modes with Automatic Mode Switching
Ultralow Dropout ILED Current Control
Output Current up to 1A
Low Noise Constant Frequency Operation
Independent Low Current/High Current
Programming and Enable Pins
Tiny Application Circuit (All Components <1mm Profile)
3mm x 4mm 12-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.
Note: LT and LTC are registered trademarks of Linear Technology Corp.
Worldwide Contacts
North America
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@eba.com.cn
Germany
Ralf Stegmann
Tel: +49 (0) 7131/9234-0
ralf@ezwire.com
Japan
Kazuto Takahashi
Tel: 81-3-5226-7291
takahashi@linear-tech.co.jp
UK & Scandinavia
Alan Timmins
Tel: +44-1-252-629937
a.timmins@ntlworld.com
Korea
Desiree Park
Tel: +82 (0) 2812 1144
desiree@ezwire.com