The adoption of automotive-grade LED lighting is progressing in terms of energy savings and design flexibility, while the number of lights and brightness levels are increasing significantly. Vehicle manufacturers are demanding simpler circuits for taillights and license plate lights to reduce costs and shorten development time.
Responding to market demands, ROHM has developed its latest LED drivers, the BD183x7EFV-M series (BD18337EFV-M / BD18347EFV-M), which incorporate a patented heat dissipation circuit and individual LED control functionality.
To minimize board footprint, the output channels are grouped into a single terminal, enabling a high-performance 4-channel driver (150mA/channel) to be configured in a compact 16-pin package. Furthermore, the individual LED control function allows for the control of LEDs with different specifications using a single driver. To reduce design effort, the heat dissipation circuit simplifies the overall thermal design. The LED control function allows for individual or collective control of LEDs in case of failures to comply with motorcycle license plate lighting regulations. The individual dimming function supports sequential lighting for greater design versatility, along with protection features to safeguard the LED driver and peripheral circuitry.
Key Features
The BD183x7EFV-M series (BD18337EFV-M / BD18347EFV-M) leverages the heat dissipation circuit and individual LED control function to significantly reduce both the board area and application design effort for LED lights.
1. Minimizes the overall board area
. 1-1. The heat distribution circuit enables high-power, 4-channel output in a compact size.
ROHM's heat distribution circuit groups the heat dissipation terminals into a single terminal to achieve higher output power (150 mA/channel) in a compact 16-pin form factor, while increasing the maximum number of channels to 4. In conventional vehicle taillight systems, 2 LED drivers are needed to power 4 LED strings. ROHM's new ICs allow all 4 strings to be controlled by a single driver, significantly reducing the number of parts and the mounting area.
1-2. Individual LED control function controls 2 LEDs with different specifications
ROHM's new ICs integrate an individual LED control function that can simultaneously control 2 different types of LEDs, minimizing the board area by reducing the number of integrated circuits by half compared to existing systems, which require 2 integrated circuits to drive the same number of LEDs.
2. Significantly reduces design effort
2-1. ROHM's heat dissipation circuit minimizes thermal design person-hours.
The BD183x7EFV-M series incorporates a thermal distribution circuit that groups the multiple terminals of the heat dissipation circuit into one, significantly reducing design effort by allowing the thermal design normally required for each channel to be completed in a single design step.
2-2. The individual LED control function supports the development of variants for different regions.
The built-in control function allows selection between collective or individual LED shutdown in the event of a rear light failure. Designers can choose to switch off all LEDs or only the faulty string, enabling compliance with multi-regional regulations with a single configuration and significantly reducing redesign man-hours.
3. Compatibility with sequential lighting provides greater design versatility.
The BD183x7EFV-M series provides an individual dimming function for sequential lighting by incorporating external resistors.
4. Multiple built-in protection functions protect the circuit during abnormal situations.
Open/short circuit detection for vehicle lights, abnormal situation detection for each channel, and other protection functions prevent damage to the circuit, LED driver, and peripherals.
Electrical characteristics
(see table)
Availability: immediate
Application examples
• Rear lights (stop/tail lights)
• Fog lights
• Turn signals
• License plate lights
• DRLs (daytime running lights)
• …and other LED lighting systems for 2 and 4 wheeled vehicles.
