Charge pump does double duty

Dallas, Tex. — Diodes Inc. has introduced a dual-function charge pump, capable of handling the requirements of LED driving in LCD backlighting, and flashlight or camera flash circuits. The AL3157, supplied in a 12-pin, 3 x 3-mm DFN package only needs three external capacitors, making it well suited for portable, battery-powered products such as ruggedized mobile phones.

Operating from a 2.7-V to 5.5-V supply, the high-efficiency charge pump drives three channels at up to 30 mA for small LCD screen backlighting and a separate channel at up to 210 mA for LED flashlight or LED camera flash. The charge pump offers 93 percent power efficiency, which increases battery life, while its 1 percent current matching accuracy between channels ensures consistency in backlighting, resulting in a higher quality screen image, said Diodes.
The AL3157 uses only 2 enable pins to enable and disable the associated LCD backlighting and camera flash output channels and to dim the LED current delivered using pulse width modulation. All output channels incorporate short-circuit, thermal and under-voltage lockout protection.

Pricing:$0.25 each in quantities of 1,000.