• 简体中文
• English

LTC3891 - Low IQ, 60V Synchronous Step-Down Controller

The LTC3891 is a high performance step-down switching regulator DC/DC 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.

The 50μA no-load quiescent current extends operating run time in battery-powered systems. OPTI-LOOP® compensation allows the transient response to be optimized over a wide range of output capacitance and ESR values. The LTC3891 features a precision 0.8V reference and power good output indicator. A wide 4V to 60V input supply range encompasses a wide range of intermediate bus voltages and battery chemistries. The output voltage of the LTC3891 can be programmed between 0.8V to 24V.

The TRACK/SS pin ramps the output voltages during start-up. Current foldback limits MOSFET heat dissipation during short-circuit conditions. The PLLIN/MODE pin selects among Burst Mode operation, pulse-skipping mode, or continuous conduction mode at light loads.

Features Wide VIN Range: 4V to 60V (65V Abs Max) Low Operating IQ: 50μA Wide Output Voltage Range: 0.8V ≤ VOUT ≤ 24V RSENSE or DCR Current Sensing Phase-Lockable Frequency (75kHz to 750kHz) Programmable Fixed Frequency (50kHz to 900kHz) Selectable Continuous, Pulse-Skipping or Low Ripple Burst Mode® Operation at Light Load Selectable Current Limit Very Low Dropout Operation: 99% Duty Cycle Adjustable Output Voltage Soft-Start or Tracking Power Good Output Voltage Monitor Output Overvoltage Protection Low Shutdown IQ: < 14μA Internal LDO Powers Gate Drive from VIN or EXTVCC No Current Foldback During Start-Up Small 20-Pin 3mm × 4mm QFN and TSSOP Packages Typical Application

Applications Automotive Always-On Systems Battery Powered Digital Devices Distributed DC Power Systems Packaging

Demo Boards