LP5520

The LP5520 is an RGB backlight LED driver for small format color LCDs. RGB backlights enable better colors on the display and power savings compared with white LED backlights. The device offers a small and simple driver solution without need for optical feedback. Calibration in display module production can be done in one temperature. The LP5520 produces true white light over a wide temperature range. Three independent LED drivers have accurate programmable current sinks and PWM modulation control. Using internal calibration memory and external temperature sensor, the RGB LED currents are adjusted for perfect white balance independent of the brightness setting or temperature. The user programmable calibration memory has intensity vs temperature data for each color. This white balance calibration data can be programmed to the memory on the production line of a backlight module.

The device has a magnetic boost converter that creates a supply voltage of up to 20 V LED from the battery voltage. The output can be set at 1-V steps from 5 V to 20 V. In adaptive mode the circuit automatically adjusts the output voltage to minimum sufficient level for lowest power consumption. Temperature is measured using an external temperature sensor placed close to the LEDs. The second ADC input can be used, for example, for ambient light measurement.