Single IC controls entire LED matrix headlight

October 16, 2014 // By Christoph Hammerschmidt
Adaptive matrix LED headlights are one of the innovations in the automotive industry that clearly improve driving safety and thus spread quickly across vendors. The obstacle to adopt them also in the more affordable vehicle classes lies in its cost, and in this context matrix drivers are a major cost block. Texas Instruments (TI) now has introduced a LED matrix manager that integrates these functions on a single chip, shattering the price barrier to the lower end. As a side effect, the chip enables designers to drastically reduce the size of their PCBs.

TI's TPS92661-Q1 is a compact, scalable solution that enables automobile manufacturers to create LED headlamps that vary beam patterns and intensity dynamically for optimum roadway illumination and enhanced driver safety. Featured in premium vehicles today and proliferating into mainstream models in the coming years, adaptive headlamp systems automatically manage the direction and intensity of high and low beams.

The TI chip enables the implementation of shunt FET dimming arrays of high-brightness LEDs and includes 12 individually controlled MOSFET switches to steer current through or around the connected LEDs, thereby providing individual pixel-level light adjustment. A serial communication port facilitates control and diagnostic functions from a master microcontroller, such as TI's AEC-Q100-qualified C2000 Piccolo.

Until now, headlamp beam forming and directional control in an adaptive headlamp design required considerable board space to house bulky discrete circuits, including multiple transistors, gate drivers and glue logic. A single TPS92661-Q1 replaces this complex design, reducing board space by 73 %, and enables an all-solid-state headlamp system with no moving parts that can wear out, such as motors or actuators.

The TPS92661-Q1 controls up to 96 LEDs from a single serial port for headlamp beam forming and directional control. Brightness control is achieved through individual 10-bit pulse-width modulation (PWM) brightness control LED for pixel-level light intensity adjustment. LEDs are protected by an open/short fault diagnostics; in the event of headlamp failures or damage, the system issues a message to the master microcontroller which then can pass an alert to the driver. and reporting alerts driver via the master microcontroller .

The chip comes in a 48-pin HTQFP package and is priced at US$3.70 each in 1,000-unit quantities.

For more information, samples and evaluation modules, visit www.ti.com/tps92661q-pr-eu.

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