Driver dims multicolour LED lighting

High-efficiency driver is designed to drive tricolour RGB LEDs for fun lighting or enhanced LCD backlighting in portable applications.

Available now from ON Semiconductor, the NCP5623 is a high-efficiency triple-output LED driver with I2C interface and built-in gradual dimming.

The device is specifically designed to drive tricolour RGB (red, green, blue) LEDs for fun lighting or enhanced LCD backlighting in portable applications such as cellphones and MP3 players.

Offered in the compact LLGA-12 package, the NCP5623 is the smallest RGB LED charge pump driver housed in a nonbump plastic package on the market today.

"The use of LEDs to generate lighting patterns continues to enhance the appeal and interactivity of portable devices", says Manor Narayanan, Vice President and General Manager of ON Semiconductor's Digital and Consumer Products Group.

"ON Semiconductor's highly efficient and ultra-small NCP5623 LED driver offers a unique built-in control algorithm that generates plug-and-play lighting effects with a vast palette of colours for portable applications".

The NCP5623 LED driver performs autonomous operations on the command of the processor via its I2C interface.

Its three independently controlled current outputs - with +/-0.5% typical matching tolerance and 32 current levels - allow the display of more than 32,000 colours with a tricolour RGB LED.

The device features an integrated gradual dimming feature, which progressively increases or decreases output current to produce a theatrical fade-in/fade-out effect.

The use of a logarithmic current profile ensures the light and colour changes appear smooth and linear to human eyes.

To help maximise battery life, the NCP5623 achieves 94% peak efficiency with less than 1uA standby current over the operating range of a lithium-based battery.

Despite the small IC package, the device requires only four passive components to operate in a typical application.

The device also features short-circuit and overvoltage protection, which protects the system in case of LED failure.

The NCP5623 is housed in the lead-free (Pb-free) 2.0 x 2.0 x 0.55mm LLGA-12 package and is budgetary priced at US $0.55 per unit for 3000-unit quantities.

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