Product category: Power Supply ICs and Controllers
News Release from: Linear Technology Corp | Subject: LT3497
Edited by the Electronicstalk Editorial Team on 21 May 2007
Convertor adds flexibility to handset
backlighting
Dual step-up DC/DC convertor drives up to 12 white LEDs from a single Li-ion cell.
The LT3497 is a dual full-featured step-up DC/DC convertor from Linear Technology that is designed to drive up to 12 white LEDs from a Li-ion input Its high efficiency, fixed frequency operation ensures uniform LED brightness, low noise and maximum battery life, and the on-chip Schottky diodes eliminate both the added cost and space of external diodes
This article was originally published on Electronicstalk on 28 Jul 2004 at 8.00am (UK)
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The LT3497's two independent convertors are capable of driving asymmetric LED strings (up to six in series per convertor) from an input voltage of 2.5 to 10V.
Its 3 x 2mm DFN package and tiny externals provide a very compact footprint for space-constrained handheld applications.
The LT3497's 2.3MHz constant switching frequency enables the designer to minimise both solution footprint and switching noise.
Its 2.5 to 10V input voltage range enables the device to operate in applications from single or dual cell Li-ion powered handheld devices as well as 5V fixed inputs.
Its high side current sense enables each string of LEDs to be driven by a single wire.
The LT3497 acts as a constant current source, delivering the same current to each white LED, regardless of fluctuations in the LED's forward voltage drop which varies with temperature, manufacturing tolerances and age, ensuring uniform LED brightness.
Although on the same chip, the independent step-up convertors are capable of driving asymmetric LED strings, with independent dimming and shutdown control of each string.
Additional features include internal soft-start/inrush current limiting, and open LED protection.
The combination of the LT3497's high efficiency, versatility, low noise, and extremely small total-solution footprint make it ideal for variety of backlighting applications that require many white LEDs in a tiny form factor.
The LT3497 is available from stock in a 3 x 2mm DFN-10 package.
Pricing starts at $1.70 for 1000-piece quantities. Request a free brochure from Linear Technology Corp ...
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