MAX16834_10 Datasheet, PDF (1/23 Pages) Maxim Integrated Products – High-Power LED Driver with Integrated High-Side LED Current Sense and PWM Dimming MOSFET Driver

19-4235; Rev 3; 1/10
EVAALVUAAILTAIOBNLEKIT
High-Power LED Driver with Integrated High-Side LED
Current Sense and PWM Dimming MOSFET Driver
General Description
The MAX16834 is a current-mode high-brightness LED
(HB LED) driver for boost, boost-buck, SEPIC, and high-
side buck topologies. In addition to driving an n-channel
power MOSFET switch controlled by the switching con-
troller, it also drives an n-channel PWM dimming switch to
achieve LED PWM dimming. The MAX16834 integrates
all the building blocks necessary to implement a fixed-fre-
quency HB LED driver with wide-range dimming control.
The MAX16834 features constant-frequency peak cur-
rent-mode control with programmable slope compensa-
tion to control the duty cycle of the PWM controller.
A dimming driver designed to drive an external n-chan-
nel MOSFET in series with the LED string provides
wide-range dimming control up to 20kHz. In addition to
PWM dimming, the MAX16834 provides analog dim-
ming using a DC input at REFI. The programmable
switching frequency (100kHz to 1MHz) allows design
optimization for efficiency and board space reduction.
A single resistor from RT/SYNC to ground sets the
switching frequency from 100kHz to 1MHz while an
external clock signal at RT/SYNC disables the internal
oscillator and allows the MAX16834 to synchronize to
an external clock. The MAX16834’s integrated high-
side current-sense amplifier eliminates the need for a
separate high-side LED current-sense amplifier in
boost-buck applications.
The MAX16834 operates over a wide supply range of
4.75V to 28V and includes a 3A sink/source gate driver
for driving a power MOSFET in high-power LED driver
applications. It can also operate at input voltages
greater than 28V in boost configuration with an external
voltage clamp. The MAX16834 is also suitable for DC-
DC converter applications such as boost or boost-
buck. Additional features include external enable/
disable input, an on-chip oscillator, fault indicator out-
put (FLT) for LED open/short or overtemperature condi-
tions, and an overvoltage protection sense input
(OVP+) for true overvoltage protection.
The MAX16834 is available in a thermally enhanced
4mm x 4mm, 20-pin TQFN-EP package and in a thermal-
ly enhanced 20-pin TSSOP-EP package and is specified
over the automotive -40°C to +125°C temperature range.
Applications
Single-String LED LCD Backlighting
Automotive Rear and Front Lighting
Projection System RGB LED Light Sources
Architectural and Decorative Lighting (MR16, M111)
Spot and Ambient Lights
DC-DC Boost/Boost-Buck Converters
Features
o Wide Input Operating Voltage Range (4.75V to
28V)
o Works for Input Voltage > 28V with External
Voltage Clamp on V_IN for Boost Converter
o 3000:1 PWM Dimming/Analog Dimming
o Integrated PWM Dimming MOSFET Driver
o Integrated High-Side Current-Sense Amplifier for
LED Current Sense in Boost-Buck Converter
o 100kHz to 1MHz Programmable High-Frequency
Operation
o External Clock Synchronization Input
o Programmable UVLO
o Internal 7V Low-Dropout Regulator
o Fault Output (FLT) for Overvoltage, Overcurrent,
and Thermal Warning Faults
o Programmable True Differential Overvoltage
Protection
o 20-Pin TQFN-EP and TSSOP-EP Packages
Ordering Information
PART
TEMP RANGE
PIN-PACKAGE
MAX16834ATP+
-40°C to +125°C
20 TQFN-EP*
MAX16834ATP/V+
-40°C to +125°C
20 TQFN-EP*
MAX16834AUP+
-40°C to +125°C
20 TSSOP-EP*
MAX16834AUP/V+ -40°C to +125°C
20 TSSOP-EP*
+Denotes a lead(Pb)-free/RoHS-compliant package.
*EP = Exposed pad.
/V denotes an automotive qualified part.
Simplified Application Circuit
VIN
BOOST LED DRIVER
LED+
IN
NDRV
LEDs
ON
MAX16834
OFF
PWMDIM
CS
LED-
ANALOG
DIM
REFI
DIMOUT
PGND
SENSE+
Pin Configurations appear 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.