Products, Materials + Tools | Jul 26, 2010

Independently Dimmable, Three-Channel LED Drivers for Compact and Simple Driver Circuits

The MAX16824/MAX16825 three-channel LED drivers operate over a 6.5V to 28V input voltage range. These devices provide three open-drain constant-current-sinking outputs that are rated to 36V and deliver up to 150mA of current to each string of high-brightness LEDs (HB LEDs).

The current at each output is programmable by means of an external current-sense resistor. The MAX16824 features three PWM inputs that control the duty cycle of the output current, allowing a wide LED dimming range to be implemented. The PWM inputs also function as on/off control for each corresponding output. The MAX16825 offers a 2Mbps, 4-wire serial interface, a 3-bit shift register, and a 3-bit transparent latch. The serial interface allows a microcontroller to configure the output channels using four inputs (DIN, CLK, LE, active-low OE) and a data output (DOUT). DOUT allows multiple drivers to be cascaded and operated together.

The MAX16824/MAX16825's on-board pass elements minimize the need for external components, while at the same time, providing ±5% LED current accuracy. Additional features include a +5V (±5%) regulated output with 4mA output current capability and thermal protection.

The MAX16824/MAX16825 are available in a thermally enhanced 16-pin TSSOP-EP package and specified over the -40°C to +85°C temperature range.

Key Features:
6.5V to 28V Operating Range
Outputs Connected to 36V Supply for Long LED Strings
Three 36V-Rated Output Channels with Independently Adjustable LED Current
150mA Output Current Per Channel
±5% LED Current Accuracy
PWM Dimming
Three Independent Dimming Control Inputs (MAX16824)
4-Wire Serial Interface LED Current Chopping (MAX16825)
+5V (±5%) Regulated Output with 4mA Source Capability
Fast Transient Dimming Response
200mV Current-Sense Reference Reduces Power Loss
Thermal Shutdown
-40°C to +85°C Operating Temperature Range
Thermally Enhanced, 16-Pin TSSOP Exposed Paddle Package

Architectural and Decorative Lighting
Automotive Lighting
Indoor and Outdoor LED Video Displays
Industrial Lighting
LCD Display Backlighting
Mood Lighting
About Maxim Integrated Products:
Maxim Integrated Products was established in 1983. In 2001, Maxim acquired Dallas Semiconductor. Our mission is to continuously invent high-quality analog and mixed-signal engineering solutions that add value to our worldwide customers' microprocessor-based electronics. We have consistently served both our customers and our stockholders by meeting our cost and performance goals, minimizing time-to-market, and maximizing our engineering productivity.