ADI LTC3851AIUD-1#TRPBF

The LTC3851A-1 is a high performance synchronous step-down switching regulator controller that drives an all N-channel synchronous power MOSFET stage. A constant frequency current mode architecture allows a phase‑lockable frequency of up to 750kHz. OPTI-LOOP compensation allows the transient response to be optimized over a wide range of output capacitance and ESR values. The LTC3851A-1 features a precision 0.8 reference and a power good indicator. A wide 4V to 38V (40V absolute maximum) input supply range encompasses most battery configurations and intermediate bus voltages. The TK/SS pin ramps the output voltage during start‑up and shutdown with coincident or ratiometric tracking. Current foldback limits MOSFET heat dissipation during shortcircuit conditions. The MODE/PLLIN pin selects among Burst Mode operation, pulse-skipping mode or continuous inductor current mode at light loads and allows the IC to be synchronized to an external clock. The LTC3851A-1 contains an improved PLL compared to the LTC3851-1. The LTC3851A-1 is identical to the LTC3851A except that the ILIM pin is replaced by PGOOD.

• Wide VIN Range: 4V to 38V Operation
• RSENSE or DCR Current Sensing
• ±1% Output Voltage Accuracy
• Power Good Output Voltage Monitor
• Phase-Lockable Fixed Frequency: 250kHz to 750kHz
• Dual N-Channel MOSFET Synchronous Drive
• Very Low Dropout Operation: 99% Duty Cycle
• Adjustable Output Voltage Soft-Start or Tracking
• Output Current Foldback Limiting
• Output Overvoltage Protection
• OPTI-LOOP Compensation Minimizes COUT
• Selectable Continuous, Pulse-Skipping or Burst Mode Operation at Light Loads
• Low Shutdown IQ: 20µA
• VOUT Range: 0.8V to 5.5V
• Thermally Enhanced 16-Lead MSOP or 3mm × 3mm QFN Package

• Automotive Systems
• Telecom Systems
• Industrial Equipment
• Distributed DC Power Systems