SOURCE: Maxim Integrated Products

March 10, 2008 15:20 ET

Maxim's High-Power, High-Voltage, Programmable LED Driver Is Ideal for Automotive and General Lighting Applications

SUNNYVALE, CA--(Marketwire - March 10, 2008) - Maxim Integrated Products (PINKSHEETS: MXIM) introduces the MAX16816, a high-voltage, programmable, high-brightness (HB) LED driver for automotive and general lighting applications.

Synopsis for Investor:

--  The MAX16816 is specifically tailored to meet the requirements of the
    latest front light automotive designs, such as high- and low-beam
    assemblies, adaptive front light systems, daytime running lights
    (DRLs), and fog lamps.

--  The device is also ideal for high-power flood lighting, down lighting,
    and projection systems that require high-current LED drive
    capabilities.

--  The MAX16816's ability to program LED current eliminates the need for
    binning LEDs according to their brightness variations. By allowing LED
    current adjustment, the MAX16816 compensates for brightness variations
    during manufacturing.

--  This highly integrated HB LED driver operates from a 5.4V to 76V input
    voltage range, ensuring cold-start and load-dump (up to 80V)
    compliance. High-voltage capability improves the reliability of the LED
    lamp/driver combo. The 76V rating of this device allows automotive
    lighting manufacturers to offer LED lamp systems that are even more
    reliable than before.

Far more versatile than competitive devices, the MAX16816 provides many user-programmable features through on-chip nonvolatile EEPROM registers. Using a microcontroller and a single-wire interface, the programming is done either at the factory or by the designer in the field.

The MAX16816 integrates all the building blocks necessary to implement fixed-frequency HB LED drivers with wide-range dimming control. It is configurable to operate as a step-down (buck), step-up (boost) or step-up/down (buck-boost) current regulator. The device also includes an integrated, differential current-sense amplifier and a floating dimming driver capable of driving an n-channel MOSFET.

The MAX16816 is specifically tailored to meet the requirements of the latest front light automotive designs, such as high- and low-beam assemblies, adaptive front light systems, daytime running lights (DRLs), and fog lamps. The device is also ideal for high-power flood lighting, down lighting, and projection systems that require high-current LED drive capabilities.

Advanced Programming Overcomes Traditional Design/Manufacturing Problems

Because of its sophisticated programming capabilities, the MAX16816 overcomes many problems and design limitations in older generation LED drivers.

Designers have long struggled to ensure even brightness among LEDs. Typically a customer had to adjust the LED current to match the LED bin (brightness). This increased manufacturing complexity and cost. Now, however, the MAX16816's ability to program LED current eliminates the need for binning LEDs according to their brightness variations. By allowing LED current adjustment, the MAX16816 compensates for brightness variations during manufacturing.

Traditional LED drivers also offered customers no freedom to select the gate-driver voltage. Designers were thus forced to accept devices with expensive, high-gate-voltage MOSFETs. Now the designer can program the output gate-drive voltage to a value lower than the full-supply voltage. This means that lower cost, low-gate-drive-voltage MOSFETs can be used in the design.

It was not possible to fine-tune the controller's switching frequency. Because of the MAX16816's programming capabilities, the switching frequency and rise/fall time of LED current during PWM dimming can now be fine-tuned, which helps reduce both system-level noise and EMI.

Software-controlled adjustment of blanking time was also not available. Because the MAX16816 allows the blanking-time value to be programmed into a device, this parameter can now be adjusted easily at the design stage. The capability of adjusting blanking time improves the LED driver's immunity to noise caused by high levels of switching current.

The MAX16816's programmable features include: soft-start, LED current adjust, external MOSFET gate-driver supply voltage, slope compensation, blanking time, and enabling/disabling of the internal PWM oscillator. This high level of programmability ensures the design flexibility needed for efficiency, size, and minimal EMI.

The Special Benefits of High Power and High Voltage

The highly integrated MAX16816 HB LED driver operates from a 5.4V to 76V input voltage range, ensuring cold-start and load-dump (up to 80V) compliance. The driver enables high-efficiency operation and a wide dimming range (1000:1) with analog or PWM control. The analog control signal is compared to an on-board 200Hz ramp and can be used to simplify designs with multilevel brightness adjustment requirements. The LED current control accuracy is +/-5% over the entire automotive operating temperature range for excellent brightness matching.

High-voltage capability improves the reliability of the LED lamp/driver combo. The 76V rating of this device allows automotive lighting manufacturers to offer LED lamp systems that are even more reliable than before.

Additional LED Driver Benefits

The MAX16816 enables flexible design with various topologies: buck, boost, buck-boost, and SEPIC. Peak-current-mode control with leading-edge blanking simplifies control-loop design. Internal slope compensation ensures stable operation at duty cycles above 50%.

A very low 100mV LED current-sense reference and an internal gate driver with 1.4A/2A source/sink capability allow for high-efficiency and, therefore, minimal heat dissipation. The driver's high-current capability is ideal for designing high-power LED systems. An integrated floating LED current-sense amplifier and dimming MOSFET driver minimize component count and ensure high reliability. A dedicated enable/shutdown input ensures that the shutdown-mode current remains below 45 microamps.

The MAX16816 rugged LED driver also features output overvoltage, overcurrent, overtemperature, and LED short protection.

The MAX16816ATJ+ is rated for the -40 degrees Celsius to +125 degrees Celsius automotive temperature range. It is available in a lead-free, 32-pin TQFN package with exposed pad. Prices start at $2.33 (1000-up, FOB USA). For more information please visit: http://www.maxim-ic.com/Programmable-LED-Driver

Maxim Integrated Products, a two billion dollar company, designs and manufactures ICs for analog and mixed-signal applications. The company's broad portfolio of 27 product lines is among the industry's deepest, with over 5400 products.

Contact Information

  • Editors' Contact:
    Drew Ehrlich
    Public Relations
    408-737-7600

    Readers' Contact:
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