LED backlight driver retains constant brightness of in-car displays

Maxim Integrated Products, Inc. has launched the four-channel, low-voltage MAX25512 automotive LED backlight driver with an integrated boost converter. The company claims it is the only integrated solution that retains full, constant brightness of in-car displays even during extreme cold-crank conditions down to 3-V input voltage.

Other advantages of the integrated LED backlight driver include a reduction in board space, lower bill-of-material (BOM) cost, and high efficiency. The single-chip LED driver eliminates an external MOSFET and current sense resistor and integrates I2C communication, which all help to lower the BOM cost and reduce board space by 30 percent. In addition, the LED driver includes four 12-mA channels, claiming the industry’s highest efficiency (91%) at 2.2-MHz operation.

The MAX25512 integrates a boost converter and current sense resistor, which eliminates the need for an external MOSFET typically required to drive automotive displays. The integrated I2C communication interface is used to display settings and diagnostics, and an integrated hybrid dimming function reduces electromagnetic interference (EMI) and improves the dimming ratio.

Although automotive start-stop systems increase fuel economy, they can challenge the power delivery system to maintain the same level of display brightness during re-start, said Maxim Integrated.

The MAX25512’s 3-V input voltage and 91-percent efficiency at 2.2-MHz operation is said to deliver full, constant brightness of in-car displays during demanding cold crank/start-stop conditions. It operates down to 3 V after startup without the addition of a pre-boost converter, which protects the display from the power disruptions. Diagnostic functions such as SHORT to GND on each current sink alerts the microcontroller and individual channel pulse width modulation (PWM) settings through the I2C interface to ensure a safer and higher quality display, said Maxim Integrated.

The MAX25512 backlight LED driver is offered in a 24-pin, 4 × 4 × 0.75-mm quad flat no-lead (QFN) package. The LED driver and MAX25512EVKIT# evaluation kit are available now from Maxim Integrated and authorized distributors.