DESCRIPTION
The MSL2042 has a single PWM input for frequency and dimming control of all four strings, and automatically phase shifts the string drive signals. An external current sense resistor for each string sets full-scale LED current and is adjustable for all strings equally with an internal 8-bit DAC. The MSL2041/2 adaptively control up to two DC-DC or off-line converters that power the LEDs using Atmel's proprietary efficiency optimizer. The efficiency optimizer minimizes power use while maintaining LED current accuracy. Cascade multiple MSL2041/2s to automatically negotiate the optimum power supply voltage when driving more than four strings from a single power supply. The MSL2041/2 feature fault control for open-circuit LED strings, LED short-circuits and device over-temperature conditions. When an open-circuit or short-circuit condition is detected, the MSL2041/2 turn off the faulty string and pull the open-drain fault output low. The MSL2041/2 operate independently with PWM LED dimming control from an applied signal, or are controlled by an external microcontroller or FPGA through the I2C serial interface.
Atmel
