ROHM develops LED driver compatible with 3- to 12-inch in-vehicle displays

ROHM, the German semiconductor manufacturer, has announced the availability of the latest LED driver IC, the BD81A76EFV-M, optimised for LCD backlight in instrument clusters, centre information displays and car navigation.

Unlike conventional drivers with four channels that support LCDs up to 8 inches, this IC provides six channels of output (with 120mA per channel) that can support LCD panels of up to 10-12 inch class. At the same time, original buck-boost control ensures compatibility with both small and large LCDs using a single driver. This makes it possible to develop a common design of the LCD control board suitable for conventional panels along with the latest large-size displays.

In recent years, to improve both visibility and design in the automotive field, LCDs are being used in an increasing number of systems including instrument clusters, head-up displays and car navigation. In addition, larger screen sizes are being demanded. They require a greater number of high brightness LEDs for backlight as well as LED drivers featuring multi-channel operation and advanced dimming features that can prevent flicker effects.

In response to this increasing market need, ROHM says it has leveraged its industry-leading analog design technology and incorporated proprietary technologies into its LED drivers to achieve flicker-free operation and to contribute to a common control board design. The BD81A76EFV-M also allows designers to use larger LCD panels in-vehicle applications.

Stefan Drouzas, product marketing manager automotive display products, ROHM Semiconductor said, “ROHMs new LED driver allows flexibility of design in modern display architectures and ensures backwards compatibility providing cost-effectiveness.”

ROHM says it is committed to continuously contribute to technological innovation in the automotive sector by developing products that achieve greater optimisation and energy savings in-vehicle systems.

Key Features
Original buck-boost control supports a common control board design
The BD81A76EFV-M incorporates proprietary buck-boost control to provide greater application flexibility in LCD applications. In contrast to conventional 6channels backlight LED drivers utilising only boost control. Although conventional LED drivers are only capable of driving 36 to 60 LEDs (6-10 LEDs/channel), ROHM’s new driver IC expands the range from 6 to 60 LEDs (1-10 LEDs/channel). This ensures the support of not only larger displays but also small and medium size panels as well using a single driver, contributing to a common design of control board.

Compatibility with the latest 12-inch displays using 6-channel output
Incorporating a constant current driver with low heat generation enables a best-in-class 6 channels LED current output of 120mA per channel. Unlike conventional 4 channels products that support LCDs up to 8 inch, ROHM’s new driver can accommodate larger panels in the 10-12 inch class. In addition, original PWM dimming technology (patent no. 2018-169705) provides a dimming ratio of 10,000:1, improving visibility and greater design flexibility for center information displays and instrument clusters.

Low standby current minimises power consumption
Leveraging analog design expertise and process technologies allowed ROHM to reduce standby current consumption to just 10µA. This reduces power consumption to less than 1/3 compared with functionally equivalent products featuring a standby current of 40µA (typ.).

In addition to obtaining qualification under the international AEC-Q100 standard for automotive reliability, the BD81A76EFV-M integrates a spread spectrum function as a countermeasure against EMI that allows it to clear CISPR25 noise requirements for vehicle applications. The result is stable operation in automotive systems sensitive to noise.

As per company reports, the driver will be available for the OEMs later in 2019.