60V 2MHz Synchronous 4-Switch Buck-Boost LED Driver Controller

The LT8391A is a synchronous 4-switch buck-boost LED controller that regulates LED current from input voltage above, below, or equal to the output voltage. The proprietary peak-buck peak-boost current mode control scheme allows adjustable and synchronizable 600kHz to 2MHz fixed frequency operation, or internal 25% triangle spread spectrum operation for low EMI. With 4V to 60V input, 0V to 60V output, and seamless low noise transitions between operation regions, the LT8391A is ideal for LED driver and battery charger applications in automotive, industrial, and battery-powered systems.

The LT8391A provides both internal (up to 128:1) and external (up to 2000:1) LED current PWM dimming with a high-side PMOS switch. Two CTRL pins provide flexible 20:1 analog dimming with ±3% LED current accuracy at 100mV full scale. Fault protection is provided to detect an open or short LED condition, during which the LT8391A retries, latches off, or keeps running.

Switching Frequency

Max Output Power

LT8391

Adjustable 150kHz - 650kHz

450W+

LT8391A

2MHz

50W+

Applications

* Automotive Head Lamps/Running Lamps

* High Frequency LED Lighting

* 4-Switch Single Inductor Architecture Allows VIN Above, Below or Equal to VOUT

* Up to 95% Efficiency at 2MHz

* Proprietary Peak-Buck Peak-Boost Current Mode

* Wide VIN Range: 4V to 60V

* Wide VOUT Range: 0V to 60V (51V LED)

* ±3% LED Current Accuracy

* 2000:1 External and 128:1 Internal PWM Dimming

* High Side PMOS PWM Switch Driver