Datasheet

4 Atmel LED Driver-MSL3162
Quick Start Guide
The MSL3162 is an LED string driver that drives, monitors, and dims up to 160 white LEDs (up to 10 series and up to
16 parallel) at high efficiency for LCD backlighting and signage applications. This section summarizes the capabilities of the
MSL3162 for quick evaluation.
How Many LEDS and Drivers?
The MSL3162 drives 16 strings of series-connected LEDs. The maximum number of LEDs per string is limited to 10
white LEDs by the 40V maximum string voltage rating. More series LEDs can be driven if their forward voltage (V
F
) is
lower. When an LED string is turned off, the voltage across the LEDs does not drop to zero. This allows more series LEDs
to be driven, but eliminates the MSL3162's ability to sustain a shorted LED string.
Sixteen MSL3162s can share an I
2
C/SMBus serial interface, with both individual and broadcast (all MSL3162s on a
bus) addressing. The high total LED drive capability of multiple bussed MSL3162s makes the driver suitable for LCD TV
and monitor backlights as well as LED signage and general lighting. The LED drive capability is summarized in Table 1.
LED TYPE V
F(MAX)
LEDs IN
STRING
PER
MSL3162
16 X
MSL3162s
LED POWER PER
MSL3162
LED POWER 16 X
MSL3162s
White, Green,
Blue
3.6V 10 LEDs 160 LEDs 2560 LEDs
34W
(at 60mA string current)
544W
(at 60mA string current)
Red 2.4V 15 LEDs 240 LEDs 3840 LEDs
RGB - 10 LEDs 50 RGB LEDs
800 RGB
LEDs
26W (at 60mA) 415W (at 60mA)
LEDS, Power Supplies (PSUs), and Efficiency Optimizers
The MSL3162 obtains high efficiency by adjusting up to three LED string power supplies to deliver the minimum
necessary voltage to accurately drive all LED strings connected to each LED string supply via the three Efficiency
Optimizers. Multiple MSL3162s sharing string supplies automatically negotiate the voltage among themselves using the
FBI/FBO pins. No system intervention is needed after initial configuration. Use any appropriate LED string power supply
topology, typically a DC-DC boost or buck converter with a controllable resistive feedback voltage divider.
The Efficiency Optimizer sets the LED voltage to maintain regulation on the highest voltage LED string. The better the
LED string voltage matching, the lower the dissipation the MSL3162 absorbs, and, therefore, better LED matching
improves efficiency. RGB LEDs should be driven by three separate string supplies. Also, consider using multiple string
supplies for high-power, single-color systems, such as a white backlight.
Table 1. Atmel LED Driver MSL3162 LED Drive Capability