The LT8391IUFD#PBF 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 150kHz to 650kHz fixed frequency operation, or internal ±15% 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 LT8391IUFD#PBF is ideal for LED driver and battery charger applications in automotive, industrial, and battery-powered systems.
The LT8391IUFD#PBF 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 LT8391IUFD#PBF retries, latches off, or keeps running.
Switching FrequencyMax Output PowerLT8391Adjustable 150kHz - 650kHz450W+LT8391A2MHz50W+Feature
- 4-Switch Single Inductor Architecture Allows VIN Above, Below or Equal to VOUT
- Synchronous Switching: Up to 98% Efficiency
- 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
- Integrated Bootstrap Diodes
- No Top MOSFET Refresh Noise in Buck or Boost
- Adjustable and Synchronizable: 150kHz to 650kHz
- Flicker-Free Spread Spectrum for Low EMI
- Open and Short LED Protection with Fault Reporting
- Available in 28-Lead TSSOP with Exposed Pad and 28-Lead QFN (4mm × 5mm)
Applications
- Automotive Head Lamps/Running Lamps
- High Power LED Lighting
