文档介绍:19-4235; Rev 0; 8/08
EVALUATION KIT
AVAILABLE
High-Power LED Driver with Integrated High-Side LED
Current Sense and PWM Dimming MOSFET Driver
General Description Features MAX16834
The MAX16834 is a current-mode high-brightness LED o Wide Input Operating Voltage Range ( to
(HB LED) driver for boost, buck-boost, SEPIC, and high- 28V)
side buck topologies. In addition to driving an n-channel o 3000:1 PWM Dimming
power MOSFET switch controlled by the switching con- o
troller, it also drives an n-channel PWM dimming switch to Analog Dimming
achieve LED PWM dimming. The MAX16834 integrates o Integrated PWM Dimming MOSFET Driver
all the building blocks necessary to implement a fixed-fre- o Integrated High-Side Current-Sense Amplifier for
quency HB LED driver with wide-range dimming control. LED Current Sense in Buck-Boost Converter
The MAX16834 features constant-frequency peak cur-
o 100kHz to 1MHz Programmable High-Frequency
rent-mode control with programmable pensa-
Operation
tion to control the duty cycle of the PWM controller.
o External Clock Synchronization Input
A dimming driver designed to drive an external n-chan-
nel MOSFET in series with the LED string provides o Programmable UVLO
wide-range dimming control up to 20kHz. In addition to o Internal 7V Low-Dropout Regulator
PWM dimming, the MAX16834 provides analog dim- o Fault Output (FLT) for Overvoltage, Overcurrent,
ming using a DC input at REFI. The programmable and Thermal Warning Faults
switching frequency (100kHz to 1MHz) allows design
o
optimization for efficiency and board space reduction. Programmable True Differential Overvoltage
A single resistor from RT/SYNC to ground sets the Protection
switching frequency from 100kHz to 1MHz while an o 20-Pin TQFN-EP Package
external clock signal at RT/SYNC disables the internal
oscillator and allows the MAX16834 to synchronize to Ordering Information
an external clock. The MAX16834’s integrated high-
side current-sense