MAX16826_15 Datasheet, PDF (1/26 Pages) Maxim Integrated Products – Programmable, Four-String HB LED Driver with Output-Voltage Optimization and Fault Detection

MAX16826
EVALUATION KIT AVAILABLE
Programmable, Four-String HB
LED Driver with Output-Voltage
Optimization and Fault Detection
General Description
The MAX16826 high-brightness LED (HB LED) driver is
designed for backlighting automotive LCD displays and
other display applications such as industrial or desktop
monitors and LCD televisions. The MAX16826 integrates
a switching regulator controller, a 4-channel linear cur-
rent sink driver, an analog-to-digital converter (ADC),
and an I²C interface. The IC is designed to withstand
automotive load dump transients up to 40V and can
operate under cold crank conditions.
The MAX16826 contains a current-mode PWM switching
regulator controller that regulates the output voltage to
the LED array. The switching regulator section is config-
urable as a boost or SEPIC converter and its switching
frequency is programmable from 100kHz to 1MHz.
The MAX16826 includes 4 channels of programmable,
fault-protected, constant-current sink driver controllers
that are able to drive all white, RGB, or RGB plus amber
LED configurations. LED dimming control for each chan-
nel is implemented by direct PWM signals for each of the
four linear current sinks. An internal ADC measures the
drain voltage of the external driver transistors and the
output of the switching regulator. These measurements
are then made available through the I²C interface to an
external microcontroller (μC) to enable output voltage
optimization and fault monitoring of the LEDs.
The amplitude of the LED current in each linear current-
sink channel and the switch-mode regulator output volt-
age is programmed using the I²C interface. Additional
features include: cycle-by-cycle current limit, shorted
LED string protection, and overtemperature protection.
The MAX16826 is available in a thermally enhanced,
5mm x 5mm, 32-pin thin QFN package and is specified
over the automotive -40°C to +125°C temperature range.
Applications
LCD Backlighting:
Automotive Infotainment Displays
Automotive Cluster Displays
Industrial and Desktop Monitors
LCD TVs
Automotive Lighting:
Adaptive Front Lighting
Low- and High-Beam Assemblies
Typical Application Circuit and Pin Configuration appear at
end of data sheet.
Benefits and Features
• 4 Channels of Programmable, Fault-Protected,
Constant-Current Source-Driver Controllers for All
White, RGB, or RGB Plus Amber LED Configurations
• Drives One to Four LED Strings
• Individual PWM Dimming Inputs per String
• Very Wide Dimming Range
• Configurable as a boost or SEPIC Converter with
Programmable 100kHz to 1MHz Switching Frequency
for Design Flexibility
• Integrated Boost/SEPIC Controller
• External MOSFETs Allow Wide-Range LED
Current with Multiple LEDs per String
• 200kHz to 2MHz Programmable Switching
Frequency for Optimizing Size vs. Efficiency
• External Switching-Frequency Synchronization
• I²C Allows the Current-Sink Drain Voltages to be
Read to Minimize Power Dissipation and Detect LED
String Fault Conditions
• 7-Bit Internal ADC for LED Voltage Monitoring and
Optimization
• Dynamic Adjustment of LED String Currents and
Output Voltage
• Standby Mode
• Protection Features Improve Reliability
• LED Short and Open Detection
• Overvoltage and Overtemperature Protection
Ordering Information appears at end of data sheet.
Simplified Diagram
VIN
IN DL CS
FB
DIM1
DR4
DIM2 DIMMING
DIM3 INPUTS
DR1
DIM4
DL1
MAX16826
CS1
SDA I²C
SCL INTERFACE
DL4
CS4
GND
BOOST LED DRIVER
19-4047; Rev 6; 2/15