Automotive Four-Switch Buck-Boost LED Controller for Combination Head Lights

The MAX25603 is a synchronous four-switch, buckboost LED driver controller suitable for multifunction automotive combination head lamps. The controller regulates the LED current for LED string voltages from 0V to 60V. The MAX25603 can be used as a seamless buck-boost LED driver for applications that require an efficient buck-boost LED driver with synchronous rectification. The MAX25603 is ideal for high-power applications that require a current source with PWM dimming capability.

The device provides seamless transition between buck, boost, and buck-boost modes depending on the ratio of input to output voltage. The MAX25603 is ideal for LED driver applications in automotive, industrial, and other LED lighting applications. A fault flag indicates open LED or thermal shutdown conditions. The device uses Analog Devices’ proprietary average-current-mode control scheme and allows adjustable 200kHz to 440kHz fixedfrequency operation. In addition, ±6% triangular spreadspectrum is added internally to the oscillator to improve EMI performance. The MAX25603 provides both analog and digital PWM dimming in dual string applications with time sharing. A single device can be used to power a daytime running light (DRL), position light, high beam, and low beam in an automotive front headlamp. The MAX25603 integrates two high-side pMOS drivers for PWM dimming applications that require fast rising and falling edges of the LED current. It also features robust output open and short protection, is AEC qualified, and is suitable for automotive applications.

The MAX25603 uses Analog Devices’ proprietary architecture to limit LED current overshoots and overshoot durations during switchover in dual-string applications in time-sharing mode. In multistring applications in time-sharing mode, LED current overshoots during switchover between strings is minimized by an Analog Devices’ proprietary control scheme.

Applications

* Combination Automotive Head Lamps

* Automotive Ready: AEC-Q100 Qualified

* Integration Minimizes BOM for High-Brightness LED Driver, Saving Space and Reducing Cost

* Wide Input Voltage Range from 5V to 60V

* H-Bridge Single Inductor Buck-Boost Architecture

* Built-In Fast LED Current Limit During Transients

* Suitable for Dual-String Applications with Time- Sharing

* 28-Pin TSSOP with EP Pad

* Full Featured Dual String Driver

* Analog and PWM Dimming on Both Channels (EN1 and EN2)

* Analog Devices’ Proprietary Control Architecture Limits LED Current Spikes and Spike Duration in Dual-String Mode

* Flicker-Free PWM Dimming with Spread- Spectrum

* Dual Integrated pMOS Dimming FET Gate Driver

* Protection Features and Wide Temperature Range Increase System Reliability

* Short Circuit, Overvoltage, and Thermal Protection

* Fast LED Current Limit and Input Current Limiter

* -40°C to +150°C Operating Junction-Temperature Range