Automotive LED drivers control up to 192 zones

Rohm Semiconductor has launched a new BD94130xxx-M series (BD94130MUF-ME2 and BD94130EFV-ME2) of LED driver ICs for automotive LCD backlights, supporting large and higher-resolution displays that are increasingly used in car infotainment and instrument clusters for improved visibility. Applications include electronic mirrors, instrument clusters, car infotainment and head-up displays.

Using LED drivers with local dimming capabilities that can turn off only the backlight in dark areas of the LCD improves both performance and power consumption, said Rohm. Now, they are going into next-gen cockpits.

A single conventional direct-type LED driver IC controls less than 100 zones; however, this is a challenge as the number of components increases with larger displays with more zones, said Rohm.

BD94130xxx-M series of automotive LED drivers (Source: Rohm Semiconductor)

The BD94130xxx-M series can control more zones than conventional ICs, reducing the number of LEDs required. These matrix LED drivers feature an 8-line switch controller with a 24-channel current driver that can be divided into eight lines, enabling dimming of up to 192 zones of mini-LEDs for backlighting with one IC. The mini-LEDs in each zone can be independently adjusted by using a local dimming function, which contributes to a larger contrast ratio and lower power consumption displays, said Rohm.

The number of switch controller lines can be selected from three patterns (4, 6, 8) using register settings to address a variety of zones and LED current consumption specs. Built-in feedback control provides a constant feedback voltage independent of LED temperature characteristics for lower thermal design person-hours and loss ratio.

In addition, for example, the LED drivers enable operation with one-fourth the number of LED drivers compared to existing 48-zone products in current mainstream 10-inch infotainment displays that use approximately 600 zones. This decreases LED driver mounting area by approximately 84 percent, according to Rohm.

Benefits of Rohm’s BD94130xxx-M automotive LED drivers (Source: Rohm Semiconductor)

The AEC-Q100-qualified BD94130xxx-M devices are embedded 24- channel constant current drivers with 12-bit PWM dimming. The devices can set LED constant current value by setting the external ISET resistor and communication with the μ-controller via the SPI is feasible. Other features include phase-shift function, 6-bit dot correct (50% to 100%), LED open and short detection, PGATE short protection, VINSW over-voltage protection and adjacent LEDCH short detection.

Currently, the devices are available from DigiKey, Mouser and Farnell. They will be available from other online distributors as they become available.