LT3935 36V, 4A Synchronous Step-Down LED Driver with Silent Switcher

Product Details

The LT3935 is a monolithic, synchronous, step-down DC/DC converter that utilizes fixed-frequency, peak current control and provides PWM dimming for a string of LEDs. The LED current is programmed by an analog voltage or the duty cycle of pulses at the CTRL pin. An output voltage limit can be set with a resistor divider to the FB pin.

The switching frequency is programmable from 200kHz to 2MHz by an external resistor at the RT pin or by an external clock at the SYNC/SPRD pin. With the optional spread spectrum frequency modulation enabled, the frequency varies from 100% to 125% to reduce EMI.

Additional features include an LED current monitor, an accurate EN/UVLO pin threshold, open-drain fault reporting for open-circuit and short-circuit load conditions, and thermal shutdown. The LT3935 utilizes proprietary Silent Switcher technology for very low EMI.

APPLICATIONS

  • Automotive Lighting
  • Industrial and General Purpose Lighting


Features and Benefits

  • ±1.5% LED Current Regulation
  • ±1.2% Output Voltage Regulation
  • Spread-Spectrum Frequency Modulation
  • Silent Switcher® Architecture for Low EMI
  • 3.6V to 36V Input Voltage Range
  • 0V to 36V LED String Voltage
  • 200kHz to 2MHz with SYNC Function
  • 20:1 Analog or Duty Cycle LED Current Control
  • Open/Short LED Fault Indication
  • Accurate LED Current Sense with Monitor Output
  • Programmable UVLO
  • Thermally Enhanced 28-Lead (5mm × 4mm) LQFN