National Semiconductor has introduced a RGB LED driver that is suitable for portable projectors. The projectors drive three anode RGB LEDs consecutively by using a single inductor.
National LM3435 LED Driver
The LM3435 LED driver incorporates an I2C control interface that is used for controlling the LED current. The company is exhibiting the LED driver at the Guangzhou International Lighting Exhibition that is taking place in China from June 9 to 12.
A pocket or portable projector LED design incorporates a driver for the blue, green, and red LED separately and every circuit needs an inductor. National’s LED driver drives three RGB LEDs in a sequence at a frequency of more than 60Hz. This enables the driver to match the needs of the digital light processing or liquid crystal on silicone image units.
The LED driver combines active components such as the three N-channel pass switches, P-channel synchronous MOSFET, and N-channel MOSFET. It accepts an input voltage ranging between 2.7 and 5.5 V and drives uniform current pulses to blue, green, and red LEDs in a sequence. The I2C interface linearly programs the current pulses for 1023 steps. The driver can set the current pulse by using three current setting resistors between 0.5 and 2 A.