MAX16804

High-Voltage, 350mA, High-Brightness LED Driver with Analog and PWM Dimming Control

350mA High-Brightness LED Driver with On-Board 200Hz Ramp Generator Eliminates the Need for µC's PWM Dimming Signal, Simplifies LED Lighting Applications, Minimizes External Part Counts, and Saves Cost and Space

Data Sheet (Rev. 3)

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Overview

Flexible Dimming Control Simplifies Lighting System Design
- Analog or PWM Control Signal for PWM and Theater Dimming
- 200Hz On-Board Ramp Generator
- High-Voltage (Up to 40V) DIM Pin
- Additional +5V On-Board Regulator with 2mA Capability
External Synchronization and Pulse Shaping Reduce Radio Interference
- Wave-Shaped Edges Minimize EMI During PWM Dimming
- Syncs to External PWM Signal (Up to 2kHz)
Powers High-Power, High-Brightness LEDs
- 35mA to 350mA Adjustable LED Current
- 3% LED Current Accuracy
- Differential LED Current Sense
Enables High-Efficiency Designs to Minimize Heat Dissipation
- Integrated Pass Element with Low-Dropout Voltage (0.5V typ)
- 200mV Current-Sense Reference Reduces Power Losses
Thermal Shutdown and Output Short-Circuit Protection Provide Additional Safety
- 5.5V to 40V Operating Range
- -40°C to +125°C Operating Temperature Range

The MAX16804 current regulator operates from a 5.5V to 40V input voltage range and delivers 35mA to 350mA to one or more strings of high-brightness LEDs (HB LEDs). The output current of the MAX16804 is set by using an external current-sense resistor in series with the LEDs. A dual-mode DIM pin and on-board 200Hz ramp generator allow PWM dimming with an analog or PWM input signal. The analog control signal at dimming input DIM allows for a theater-dimming effect to be implemented. Fast turn-on and turn-off times ensure a wide-range PWM operation, while wave-shaping circuitry minimizes EMI. The differential current-sense input increases LED current accuracy and noise immunity. The MAX16804 is well suited for applications requiring high-voltage input and is able to withstand load-dump events up to 45V. An on-board pass element minimizes external components while providing 3% output-current accuracy. Additional features include a 5V regulated output and short-circuit and thermal protection.

The MAX16804 is available in a thermally enhanced, 5mm x 5mm, 20-pin TQFN package and is specified over the automotive -40°C to +125°C temperature range.

Applications