Analog Devices LT8391A

Description

The LT®8391A is a synchronous 4-switch buck-boostLED controller that regulates LED current from inputvoltage above, below, or equal to the output voltage. Theproprietary peak-buck peak-boost current mode controlscheme allows adjustable and synchronizable 600kHz to2MHz fixed frequency operation, or internal 25% trianglespread spectrum operation for low EMI. With 4V to 60Vinput, 0V to 60V output, and seamless low noise transitionsbetween operation regions, the LT8391A is ideal forLED driver and battery charger applications in automotive,industrial, and battery-powered systems.The LT8391A 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 detect anopen or short LED condition, during which the LT8391Aretries, latches off, or keeps running.

Features

nn 4-Switch Single Inductor Architecture Allows VINAbove, Below or Equal to VOUTnn Up to 95% Efficiency at 2MHznn Proprietary Peak-Buck Peak-Boost Current Modenn Wide VIN Range: 4V to 60Vnn Wide VOUT Range: 0V to 60V (51V LED)nn ±3% LED Current Accuracynn 2000:1 External and 128:1 Internal PWM Dimmingnn High Side PMOS PWM Switch Drivernn No Top MOSFET Refresh Noise in Buck or Boostnn Adjustable and Synchronizable: 600kHz to 2MHznn Flicker-Free Spread Spectrum for Low EMInn Open and Short LED Protection with Fault Reportingnn Available in 28-Lead TSSOP with Exposed Pad and28-Lead QFN (4mm × 5mm)

Typical applications

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

More information

• Datasheet
• IC product information