Allegro release constant current RGB driver LED NEW

Allegro introduces a new three channel constant current LED driver with on-chip oscillator for programmable brightness control. The typical application is to drive a set of red / Green / blue (RGB) LED for a pixel in a large display or camera. By 10 bits per channel (bit) pulse width modulation (PWM) can accurately control the brightness of the LED, each channel 7bit analog current control compensation to adjust the color balance. Allegro 6271A drive current up to 150mA per channel, operating voltage up to 17V. The utility model can be used for large video display, signs, architectural and decorative lighting.

The maximum operating voltage of 17V can be connected to up to 4 or more LED strings at each output. An on-chip voltage regulator provides internal logic and reduces the number of external components and connections. The control data is downloaded serially, thus minimizing the number of pins and the package size of the device. Requires only four control signals: clock, serial data, latch and output enable signal. These signals are cached into the chip to drive the next pixel in the concatenation. A novel clock regeneration architecture allows a large number of devices to be connected in series (depending on clock frequency and pixel space). Pixel space can range up to 3m (10 feet).

A6281 requires only 3 external components to configure: a resistor is used to set the maximum output current, the decoupling capacitor on the on-chip regulator, and the LED operating voltage. High integration and tiny 3 x 3mm QFN package makes board level design more compact. Allegro A6281 has a temperature range of -40 to +85 DEG C.

Source: Electronic Engineering album