Allegro's New LED Driver Brings High-End Lighting Technology to Ordinary Vehicles, Enhancing Automotive Safety

Allegro MicroSystems (hereinafter referred to as Allegro), a global leader in motion control and energy-saving system sensing technology and power semiconductor solutions, recently announced the expansion of its automotive lighting product portfolio with the launch of two new products for advanced driver assistance systems (ADAS). As a unique solution on the market, the A80803 uses multi-topology conversion and patented IP to achieve smooth high beam/low beam/high beam conversion with a single IC. The A80804 linear LED driver can provide higher power for automotive lighting applications through multiple independently configurable channels. Both products help designers reduce the number of ICs required to build higher safety automotive lighting systems, thereby achieving higher performance and more compact designs at lower system costs.

Vehicle lighting plays an important role in keeping drivers and passengers safe. According to a recent study by the Insurance Institute for Highway Safety (IIHS), nighttime driving is three times more risky than daytime driving, and vehicles equipped with IIHS "good" rated headlights have a nearly 20% lower crash rate than those rated "poor." ADAS applications and enhanced lighting features can improve nighttime road visibility and vehicle visibility, which can significantly reduce driver response time, help prevent collisions, and save lives.

The A80803 is a switch-mode constant current controller for high-power LED automotive lighting applications that solves many common pain points for headlight designers, and its innovative features make it easier for headlight designers to introduce advanced lighting features into mainstream vehicles. The A80803's multi-topology single-ended controller design combined with wide input/output voltage capabilities provides a universal solution for a variety of applications and/or multiple LEDs. SPI-based control or EEPROM-based line-side programming options for standalone operation further expand the application potential.

The A80804 is Allegro's first four-channel linear driver for high-power LEDs. In addition to target applications such as DRL/position lights and parking lights/tail lights, it can also provide lighting designers with more design flexibility for popular functions such as sequential turn signals, animation effects, and theatrical switching. The A80804 does not require switching elements or inductors, and its low EMI helps meet CISPR25 Class 5 standards. It also provides multiple analog and PWM dimming methods, dual brightness mode operation, and can be configured without a microcontroller.

“Today’s high-end and luxury cars have many comfort and safety features that often take years to find their way into lower-priced mainstream vehicles, primarily due to the cost of the solution,” said Mark Gaboriault, Allegro’s Regulator and Lighting Product Line Director. “The A80803 provides headlamp designers with a compact, cost-effective solution that automatically manages the electrical transition from low-beam to high-beam without the need for multiple LED drivers and a local microcontroller. The A80803 is a unique product that will help democratize headlamp design, improve driver and passenger safety, and enable consumers to have an engaging, personalized driving experience. With the A80804, lighting designers can now enable animation and other lighting effects in a cost-effective manner, simplifying the design process while improving visibility and driver safety, and minimizing the bill of materials (BoM).”

Features and Benefits

The A80803 includes the following first-to-market features that help simplify headlamp design and improve occupant safety.

● Multi-topology high/low beam switching, no need for a second LED driver IC

● Unique slew-control function to minimize LED current overshoot and undershoot when switching between high beam and low beam

● Two configuration options, one with factory programmed EEPROM to eliminate the need for a local microcontroller, and one with control and status register SPI interface for software control

● Extensive diagnostic capabilities for ASIL with two programmable fault pins and reporting via SPI

● Multiple methods for simulating LEDs to set/control substrate intensity, thermal foldback via NTC, or use different LEDs in the same design

● Multiple PWM LED control methods, direct PWM control of EN/PWM pins via internal PWM signal (standalone mode) or external PWM signal (MCU mode)

The A80804's innovative features help lighting designers simplify system design while improving safety:

● Four-channel linear control, each channel has an independent Enable/PWM input

● Multiple methods of PWM LED control, including automatic phase shift, via internal PWM signals (standalone mode), or external PWM signals for direct control of the EN/PWM pins (MCU mode)

● Ability to switch between low and full intensity for applications such as stop/tail lights or DRL/position lighting without the need for a local microcontroller

● Optional LED current slew rate control to adjust PWM edge time and improve EMI performance

● Multiple methods for analog LED setting/control, LED binning, NTC automatic protection or hybrid dimming

● Integrated/selectable derating for high input voltage and/or temperature

● Unique “MINOUT” feature that significantly reduces power loss by dynamically adjusting for inherent changes in LED Vf vs. temperature

● Extensive protection measures for devices and LEDs, reporting via fault pins

● Multiple devices can be connected in parallel to expand the number of LED strings

Pricing and Availability

The A80803 is available in a 32-pin 5mm × 5mm QFN package with wettable flanks and enhanced thermal resistance, while the A80804 is available in a 32-pin 5mm × 5mm QFN package with wettable flanks. For samples or other information such as product pricing, please contact Allegro Shanghai Branch or local office. For data sheets and more information on Allegro's comprehensive LED controller series (including the newly launched A80803 and A80804), please visit the Allegro website.