LTC3891 Datasheet | Linear Technology

LTC3891 Low IQ, 60V Synchronous Step-Down Controller Features n Wide VIN Range: 4V to 60V (65V Abs Max) n Low Operating IQ: 50μA n Wide Output Voltage Range: 0.8V ≤ VOUT ≤ 24V n RSENSE or DCR Current Sensing n Phase-Lockable Frequency (75k Hz to 750k Hz) n Programmable Fixed Frequency (50k Hz to 900k Hz) n Selectable Continuous, Pulse-Skipping or Low Ripple Burst Mode® Operation at Light Load n Selectable Current Limit n Very Low Dropout Operation: 99% Duty Cycle n Adjustable Output Voltage Soft-Start or Tracking n Power Good Output Voltage Monitor n Output Overvoltage Protection n Low Shutdown IQ: < 14μA n Internal LDO Powers Gate Drive from VIN or EXTVCC n No Current Foldback During Start-Up n Small 20-Pin 3mm × 4mm QFN and TSSOP Packages APPLICATIONS n Automotive Always-On Systems n Battery Powered Digital Devices n Distributed DC Power Systems DESCRIPTION The LTC®3891 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 750k Hz. The 50μA no-load quiescent current extends operating run time in battery-powered systems. OPTI-LOOP® pensation 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 enpasses 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. L, LT, LTC, LTM, OPTI-LOOP, Burst Mode, Linear Technology and the Linear logo are registered trademarks of Linear...