Analog Devices LTC3854 Product Info

• Wide Operating V_IN Range: 4.5V to 38V
• R_SENSE or DCR Current Sensing
• ±1% 0.8V Reference Accuracy Over Temperature
• 400kHz Switching Frequency
• Dual N-channel MOSFET Synchronous Drive
• Very Low Dropout Operation: 97% Duty Cycle
• Starts Up Into Pre-Biased Output
• Adjustable Output Voltage Soft-Start
• Output Current Foldback Limiting (Disabled During Soft-Start)
• Output Overvoltage Protection
• 5V LDO for External Gate Drive
• OPTI-LOOP^® Compensation Minimizes C_OUT
• Low Shutdown I_Q: 15μA
• Tiny Thermally Enhanced 12-Pin 2mm × 3mm DFN and MSOP Packages

The LTC3854 is a high performance synchronous stepdown switching DC/DC controller that drives an all N-channel synchronous power MOSFET stage.

The LTC3854 features a 400kHz constant frequency current mode architecture. The LTC3854 operates from a 4.5V to 38V (40V absolute maximum) input voltage range and regulates the output voltage from 0.8V to 5.5V.

The RUN/SS pin provides both soft-start and enable features. OPTI-LOOP compensation allows the transient response to be optimized over a wide range of output capacitance and ESR values. Current foldback limits MOSFET dissipation during short circuit conditions. Current foldback functions are disabled during soft-start.

The LTC3854 has a minimum on-time at 75ns, making it well suited for high step-down ratios. The strong onboard MOSFET drivers allow the use of high power external MOSFETs to produce output currents up to 20A.

Applications

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