Maxim Releases Programmable LED Driver For Automotive & General Lighting Applications

Maxim Integrated Products introduced the MAX16816, a high-voltage, programmable, high-brightness (HB) LED driver for automotive and general lighting applications. Claimed to be 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 is said to integrate 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 suitable for high-power flood lighting, down lighting, and projection systems that require high-current LED drive capabilities.

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 highly integrated MAX16816 HB LED driver operates from a 5.4 to 76V input voltage range, ensuring cold-start and load-dump (up to 80V) compliance. The driver’s high-power capability allows the HB levels to be achieved. 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.

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. 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 45µA.

The MAX16816ATJ+ is rated for the -40 to +125°C 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).