MAX16831_09 Datasheet, PDF (1/19 Pages) Maxim Integrated Products – High-Voltage, High-Power LED Driver with Analog and PWM Dimming Control

19-0809; Rev 1; 4/09
EVAALVUAAILTAIOBNLEKIT
High-Voltage, High-Power LED Driver with
Analog and PWM Dimming Control
General Description
The MAX16831 is a current-mode, high-brightness LED
(HBLED) driver designed to control two external
n-channel MOSFETs for the single-string LED current
regulation. The MAX16831 integrates all the building
blocks necessary to implement fixed-frequency HBLED
drivers with wide-range dimming control. The
MAX16831 is configurable to operate as a step-down
(buck), step-up (boost), or step-up/-down (buck-boost)
current regulator.
Current-mode control with leading-edge blanking simpli-
fies control-loop design. Internal slope compensation
stabilizes the current loop when operating at duty cycles
above 50%. The MAX16831 operates over a wide input
voltage range and is capable of withstanding automo-
tive load-dump events. Multiple MAX16831s can be
synchronized to each other or to an external clock. The
MAX16831 includes a floating dimming driver for
brightness control with an external n-channel MOSFET
in series with the LED string.
HBLED drivers using the MAX16831 achieve efficien-
cies of over 90% in automotive applications. The
MAX16831 also includes a 1.4A source and 2.5A sink
gate driver for driving switching MOSFETs in high-power
LED driver applications, such as front light assemblies.
The dimming control allows for wide PWM dimming at
frequencies up to 2kHz. Higher dimming ratios of up to
1000:1 are achievable at lower dimming frequencies.
The MAX16831 is available in a 32-pin thin QFN package
with exposed pad and operates over the -40°C to
+125°C automotive temperature range.
Applications
Automotive Exterior Lighting:
High-Beam/Low-Beam/Signal Lights
Rear Combination Lights (RCL)
Daytime Running Lights (DRL)
Fog Light and Adaptive Front Light Assemblies
Industrial and Architectural Lighting
Emergency Lighting
Projectors with RGB LED Light Sources
Navigation and Marine Indicators
Pin Configuration appears at end of data sheet.
Features
o Wide Input Range: 6V to 76V With Cold-Start
Operation to 5.5V
o Integrated Differential LED Current-Sense
Amplifier
o Floating Dimming Driver Capable of Driving an
n-Channel MOSFET
o 5% LED Current Accuracy
o 200Hz On-Board Ramp Syncs to External PWM
Dimming Signal
o Programmable Switching Frequency (125kHz to
600kHz) and Synchronization
o Output Overvoltage Load Dump, LED Short,
Overtemperature Protection
o Low 107mV LED Current Sense for High
Efficiency
o Enable/Shutdown Input with Shutdown Current
Below 45µA
Ordering Information
PART
TEMP RANGE
PIN-PACKAGE
MAX16831ATJ+ -40°C to +125°C
32 TQFN-EP*
+Denotes a lead(Pb)-free/RoHS-compliant package.
*EP = Exposed pad.
Typical Operating Circuits
VIN
RUV2
BUCK-BOOST CONFIGURATION
CCLMP
RCS
RUV1
VCC
LO CLMP CS- CS+
DGT
UVEN
RD
QS
CUVEN
DRV
LEDs
SNS+
DIM
DIM
SNS-
RSENSE
REG1
MAX16831
QGND
CREG1
RT
RTSYNC
HI
CF
ROV1
OV
COMP CS FB AGND SGND REG2 DRI
ROV2
R1
CREG2
C2
R2
C1
Typical Operating Circuits continued at end of data sheet.
________________________________________________________________ Maxim Integrated Products 1
For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642,
or visit Maxim’s website at www.maxim-ic.com.