High efficiency charge pump with power saving CABC mode focuses on smartphone LED backlighting

November 22, 2010 // Paul Buckley

ON Semiconductor has introduced a 6-channel, high efficiency Quad-Mode LED driver for use in the latest smartphones and other consumer handheld applications such as digital still cameras and portable media players. The Quad-Mode architecture coupled with Content Adaptive Brightness Control (CABC) claims to ensure market leading efficiency in LED backlighting using only external capacitors.

Differentiating itself from other devices currently on the market, the highly efficient CAT3649 has a total of four charge pump modes (1x, 1.33x, 1.5x and 2x), rather than the customary three. The inclusion of a 1.33x mode increases its efficiency by up to 10 percent compared to traditional charge pump LED drivers using 1.5x operation. This allows the handheld products into which it is incorporated to extend their battery life.     

The Quad-Mode fractional charge pump supports a wide range of input voltages, from 2.4 V to 5.5 V. The LED current can be adjusted by analogue dimming in 32 linear increments via the 1-wire interface. Further adjustment can be carried out through PWM. The PWM dimming control is compatible with CABC for PWM signal frequencies from 100 Hz) to 200 kHz.     


Packaging and Pricing     

The CAT3649 is offered in a compact 3.0 mm x 3.0 mm, Pb−free TQFN−16 package. Pricing for these devices is $0.49 per unit in 100,000 unit quantities.     

Visit ON Semiconductor at www.onsemi.com

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