Datasheet

4 Atmel LED Drivers-MSL2160/MSL2161
Atmel LED Drivers-MSL2160/61
Overview
The MSL2160/1 LED string controllers drive, monitor,
and dim multiple LEDs at high efficiency for LCD
backlighting and signage applications. This section
summarizes the capabilities of the MSL2160/1 for
quick evaluation.
How Many LEDs and Drivers?
The MSL2160/1 controls 16 strings of series-
connected LEDs at up to 350mA per string. Up to eight
MSL2160/1s share a serial interface. The maximum
number of LEDs per string is determined by the
maximum power supply voltage, the LED forward
voltage drop (V
F
), and the gate drive outputs of the
MSL2160/1. The MSL2160/1 FET gate drive outputs
are optimized for FETs requiring up to 10nC of charge.
LEDs, String Power Supplies
and Efficiency Optimizers (EOs)
The MSL2160/1 Efficiency Optimizer (EO) circuits
dynamically adjust up to three LED string power
supplies to the minimum voltage necessary to
accurately drive the LED strings while assuring accurate
current flow. The power supplies can use any topology,
and are typically DC-DC boost or buck, or AC-DC off-line
switcher supplies.
The MSL2160/1 allows RGB LEDs to be driven by three
separate string supplies, and feature three independent
EO outputs to maximize the efficiency for each supply.
Although not required, it is wise to use this capability
even for single-color systems, such as white backlighting
LEDs in an LCD monitor or TV application.
Timing, PWM, Intensity Controls
and Synchronization
For video applications, the PWM LED drive signals
synchronize to the LCD’s video frame timing via the
PHI input, and to the LCD’s pixel timing via the GSC
input. This synchronization eliminates beating artifacts.
Suitability for LED backlight architectures is shown in
Table 1. Area LED dimming for direct backlighting is
supported for contrast and color gamut improvement.
Motion blur is reduced by setting each LED string’s
PWM phasing individually to synchronize PWM off times
with the LCD timing.
The MSL2160/1 also includes easily controlled internal
PWM timing generation for stand alone (non-video)
LED lighting applications that do not provide external
timing sources. One MSL2160/1 simply generates
PWM timing for itself and for the other devices in a
multiple-device application. Optionally, a single external
PWM signal applied to the PWM input controls all of
the strings’ on times, with automatic progressive phase
delay available through a single control bit.
BACKLIGHT TYPE MOTION BLUR REMOVAL AREA DIMMING MANAGEMENT
STRING SUPPLY
OPTIONS
White LED - bottom edge-lit No No
Up to three efciency
optimized power supplies
White LED - top/bottom edge-lit No No
White LED - four sides edge-lit No No
White LED - direct back-lit Yes, LED string phasing Higher contrast ratio (area dimming)
RGB LED - direct back-lit Yes, LED string phasing Higher contrast ratio and color gamut
Three efciency optimized
power supplies
Table 1. LED Common Backlight Drive Architectures and Features