Atmel MSL2166 16-channel white and RGB LED driver solution

The MSL2164/MSL2166 compact, high-power LED string drivers use external current control MOSFETs to sink up to 350mA per string, with matching better than ±0.8%. The MSL2164/MSL2166 drive 16 parallel strings of 350mA per string, with current matching better than ±0.8%. The MSL2164/MSL2166 has 12-bit PWM string dimming, forward, center, reverse and reverse PWM modes, fast 20MHz SPI supports up to 8 devices/bus, and 8-bit adaptive power correction maximizes efficiency. It is mainly used in TV and desktop monitors, medical and industrial equipment, automotive audio/video display, building lighting, etc. This article introduces the main features, block diagram and typical application circuit diagram of the MSL2164/MSL2166.

16-string, White and RGB LED Drivers with Adaptive Configuration, EEPROM, and SPI/I2C/SMBus Serial Interface

The MSL2164/MSL2166 compact, high-power LED string drivers use external current control MOSFETs to sink up to 350mA per string, with matching better than ±0.8%. The MSL2164/MSL2166 drive 16 parallel strings of LEDs and offer fault detection and management of open-circuit and short-circuit LEDs.

The MSL2164/MSL2166 feature a 20MHz SPI serial interface. Both devices support video frame-by-frame LED string intensity control for up to eight interconnected devices, allowing active area dimming and phase-shifted PWM outputs. They also include an advanced PWM engine that synchronizes PWM dimming to the video signal supporting forward, center, reverse and inverse PWM modes for reduced motion blur and waterfall noise.

The MSL2164/MSL2166 adaptively control any topology DC-DC or AC/DC converter that power the LED strings. The patent-pending “Efficiency Optimizers” minimize power use while maintaining LED current accuracy.

A unique combination of LED current control and pulse width dimming management offers simple full-screen brightness control, versatile area dimming and a consistent white point. Full-scale LED regulation current is set for each string using current sense resistors and a 10-bit register that controls global string current. The 12-bit global intensity register controls PWM dimming of all strings, and each string uses a 12-bit register to control individual string PWM dimming.

The MSL2164/MSL2166 monitor the LED strings for open-circuit, short-circuit, loss-of-sync and over-temperature faults, and provide a hardware fault output (FLTB) to notify the microcontroller. Detailed fault status and control are available through the serial interface MSL2 164/MSL2166 include on-chip EEPROMs that allow customizing of the register power-up states via the serial interface.

The MSL2164/MSL2166 are offered in a 9 x 9 x 0.85mm, 64-pin TQFN package and operate over the -40℃ to 85℃ temperature range.

MSL2164/MSL2166 Key Features:

• 12-Bit PWM String Dimming

• Forward , Center, Reverse and Inverse PWM Modes

• Fast 20MHz SPI Supports Up to 8 Devices per Bus

• 8-Bit Adaptive Power Correction Maximizes Efficiency for Up to 3 String Power Supplies

• External Current Regulation MOSFETs for High Voltage and/or Current

• Drives Up to 16 Parallel LED Strings Per Device, Cascade Additional Devices for More Strings

• Supports Adaptive, Real-Time Area Dimming for Highest Dynamic Range in LCD TVs and Monitors

• Easily Implements Scrolling, 3D, and Local Dimming Algorithms

• Programmable String Phase Reduces Motion Blur and Improves Efficiency

• Global Intensity Control via SPI Serial Interface

• 0.8% String to String Matching

• PWM Dimming Synchronized to VSYNC and HSYNC Including Frequency Multipliers and Dividers

• Second Set of PWM Registers Select Alternate Brightness and Timing

• Configurable Power-up Defaults Through Internal EEPROM

• LED Open Circuit and Short Circuit Fault Detection

• Individual Fault Detection Enabled for Each String

• Over-Temperature Shutdown Protection

• Broadcast Write Simplifies Configuration

• -40℃ To +85℃ Operating Temperature Range

MSL2164/MSL2166应用:

Long-Life, Efficient LED Backlighting for:

• Televisions and Desktop Monitors

• Medical and Industrial Instrumentation

• Automotive Audio-visual Displays

Channel Signs

Architectural Lighting

图1. MSL2164/MSL2166方框图

图2. MSL2164典型应用电路图