Analog Devices LT8391

Description

The LT®8391 is a synchronous 4-switch buck-boost LEDcontroller that regulates LED current from input voltageabove, below, or equal to the output voltage. The proprietarypeak-buck peak-boost current mode control schemeallows adjustable and synchronizable 150kHz to 650kHzfixed frequency operation, or internal ±15% triangle spreadspectrum operation for low EMI. With 4V to 60V input, 0Vto 60V output, and seamless low noise transitions betweenoperation regions, the LT8391 is ideal for LED driver andbattery charger applications in automotive, industrial, andbattery-powered systems.The LT8391 provides both internal (up to 128:1) andexternal (up to 2000:1) LED current PWM dimming witha high-side PMOS switch. Two CTRL pins provide flexible20:1 analog dimming with ±3% LED current accuracy at100mV full scale. Fault protection is provided to detectan open or short LED condition, during which the LT8391retries, latches off, or keeps running.

Features

n 4-Switch Single Inductor Architecture Allows VINAbove, Below or Equal to VOUTn Synchronous Switching: Up to 98% Efficiencyn Proprietary Peak-Buck Peak-Boost Current Moden Wide VIN Range: 4V to 60Vn Wide VOUT Range: 0V to 60V (51V LED)n ±3% LED Current Accuracyn 2000:1 External and 128:1 Internal PWM Dimmingn High Side PMOS PWM Switch Drivern Integrated Bootstrap Diodesn No Top MOSFET Refresh Noise in Buck or Boostn Adjustable and Synchronizable: 150kHz to 650kHzn Flicker-Free Spread Spectrum for Low EMIn Open and Short LED Protection with Fault Reportingn Available in 28-Lead TSSOP with Exposed Pad and28-Lead QFN (4mm × 5mm)

Typical applications

• High Power LED Lighting
• Automotive Head Lamps/Running Lamps

More information

• Datasheet
• IC product information