LT8615 Datasheet

• Wide Input Voltage Range: 3V to 42V
• Wide Output Voltage Range: 0.787V to (V_IN – 0.4V)
• Ultralow Quiescent Current Burst Mode^®
• Operation:
  • <2.5μA IQ Regulating 12V_IN to 3.3V_OUT
  • Output Ripple <10mV_P-P
• Silent Switcher^® Powertrain for Ultralow EMI Emissions
• High Efficiency 2MHz Synchronous Operation:
  • Up to 93% Efficiency at 2MHz, 12V_IN to 5V_OUT
• Fast Minimum Switch-On Time: 40ns
• Very Low Dropout: 125mV at 1A
• Adjustable and Synchronizable: 400kHz to 2.5MHz
• Optional Spread-Spectrum Frequency Modulation
• Fixed Frequency Peak Current-Mode Operation
• Accurate 1V Enable Pin Threshold
• Output Soft-Start and Tracking
• Small 3mm × 3mm Side Wettable QFN Package
  • Clearance Between High Voltage and Low Voltage Pins
  • Excellent Solder Joint Reliability
• AEC-Q100 Qualified for Automotive Applications
• Temperature Grade 0: −40°C to +150°C, T_A

• Automotive and Industrial Supplies
• Low EMI Step-Down

The LT^®8615 is a compact, high efficiency, high speed synchronous monolithic step-down switching regulator that can deliver 3.5A of continuous current. The LT8615’s ultralow 2.5μA quiescent current in Burst Mode operation (with the output in full regulation) enables high efficiency down to very low load currents while keeping the output ripple below 10mV_P-P.

A SYNC pin allows synchronization to an external clock or spread-spectrum modulation for low EMI operation. Internal compensation with peak current-mode topology allows the use of small inductors and results in fast transient response and good loop stability. The EN/UV pin has an accurate 1V threshold and can be used to program V_IN UVLO or to shut down the part. A capacitor on the TR/SS pin programs the output voltage ramp rate during start-up. An open-drain PG pin flag signals when the output is within ±8% as well as fault conditions.