Automotive backlight driver with integrated boost converter
Maxim Integrated Products has introduced the four-channel, low-voltage MAX25512 automotive LED backlight driver with integrated boost converter. It is the only integrated offering that retains full, constant brightness of in-car displays even during extreme cold crank conditions down to 3-V input voltage. The single chip LED driver eliminates an external MOSFET and current sense resistor and integrates I²C communication to lower bill of material cost and reduce board space by 30 percent. The highly integrated LED driver includes four 120 mA channels with the industry’s highest efficiency at 2.2 MHz operation.
Today’s automotive start-stop systems increase fuel economy, but they can challenge the power delivery system to maintain the same level of display brightness during re-start. For example, features like display illumination upon entry can be affected by cold crank situations, with the engine drawing down the car battery enough to cause the display to turn off and back on. The MAX25512 LED backlight driver operates down to 3-V after startup without the addition of a pre-boost converter, protecting the display from these power disruptions.
“Over the next five years, the number of displays in automobiles is expected to grow to accommodate new and existing vehicle functions with the size and resolution of these displays increasing as well,” said Sang Oh, Senior Research Analyst at Omdia. “Powering these displays consistently to maintain full, constant brightness while doing so as efficiently as possible, is critical to automakers today.”
Lowest cold crank and start-stop voltage — The MAX25512’s low, 3-V input voltage and high, 91-percent efficiency at 2.2 MHz operation drives full, constant brightness of in-car displays during the most demanding cold crank/start-stop conditions. 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.
Highest integration — The MAX25512 LED backlight driver integrates a boost converter and current sense resistor and eliminates the external MOSFET typically required to drive automotive displays. Additional integration includes an I²C communication interface to display settings and diagnostics and a hybrid dimming function to reduce electromagnetic interference (EMI) and improve the dimming ratio.
Smallest size — Offered in a small 24-pin, 4- x 4- x 0.75-mm quad flat no-lead (QFN) package, the MAX25512’s high integration shrinks size by 30 percent through elimination of external components.
The MAX25512 backlight LED driver and associated MAX25512EVKIT# evaluation kit are available now from Maxim Integrated and authorized distributors.
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