Catalog
Low Input Voltage, Synchronous Step-Down DC/DC Controller
Key Features
• Charge Pump Input Range: 2.7V to 5.5V
• Controller Input Range: 4V to 38V
• Integrated Charge Pump Provides 5V Gate Drive to Logic Level MOSFETs
• RSENSEor DCR Current Sensing
• ±1.25% Output Voltage Accuracy Over Temperature
• Phase-Lockable Fixed Frequency: 250kHz to 750kHz
• Power Good Output Voltage Monitor
• Adjustable Soft-Start Voltage Ramping
• Current Foldback Disabled During Start-Up
• No Reverse Current During Soft-Start
• Selectable Constant Frequency, Pulse-Skipping, or Burst Mode Operation
• Output Overvoltage Protection
• Very Low Dropout Operation: 99% Duty Cycle
• Available in a 24-Lead (3mm × 5mm) QFN Package
Description
AI
The LTC3852 is a constant frequency, current mode step-down DC/DC controller which can be powered by an on-board charge pump. Input supplies as low as 2.7V, when doubled by the charge pump, provide 5V to the LTC3852’s control logic and gate drives, supporting a wide selection of logic-level N-channel power MOSFETs.The constant-frequency current mode architecture allows for a phase-lockable fixed frequency of up to 750kHz. The RUN pin provides a precision enable threshold while the TRACK/SS pin combines tracking and adjustable soft-start features.The MODE/PLLIN pin selects among Burst Mode®operation, pulse-skipping mode, and continuous current mode. Current foldback limits MOSFET power dissipation during short-circuit conditions. Reverse current and current foldback functions are disabled during soft-start. A power good output pin indicates when the output is within ±10% of its designed set point.ApplicationsGeneral Purpose 3.3V SystemsLithium-Ion Powered DevicesDistributed DC Power Systems