LTC3891 Series

Low IQ, 60V Synchronous Step-Down Controller

Catalog

Low IQ, 60V Synchronous Step-Down Controller

Part	Output Configuration	Supplier Device Package	Mounting Type	Topology	Operating Temperature [Min]	Operating Temperature [Max]	Frequency - Switching [Max]	Frequency - Switching [Min]	Voltage - Supply (Vcc/Vdd) [Max]	Voltage - Supply (Vcc/Vdd) [Min]	Function	Output Phases	Number of Outputs	Control Features	Package / Case	Output Type	Duty Cycle (Max) [Max]	Package / Case [custom]	Package / Case [custom]	Package / Case [custom]
Analog Devices LTC3891EUDC#TRPBF	Positive	20-QFN (3x4)	Surface Mount	Buck	-40 °C	125 ¯C	535 kHz 835 kHz	105 kHz 350 kHz	60 V	4 V	Step-Down	1	1	Current Limit Enable Frequency Control Power Good Soft Start Tracking	20-WFQFN Exposed Pad	Transistor Driver	99 %
Analog Devices LTC3891IFE#PBF	Positive	20-TSSOP-EP	Surface Mount	Buck	-40 °C	125 ¯C	535 kHz 835 kHz	105 kHz 350 kHz	60 V	4 V	Step-Down	1	1	Current Limit Enable Frequency Control Power Good Soft Start Tracking		Transistor Driver	99 %	0.173 in 4.4 mm	Exposed Pad	20-TSSOP
Analog Devices LTC3891MPUDC#TRPBF	Positive	20-QFN (3x4)	Surface Mount	Buck	-55 °C	150 °C	535 kHz 835 kHz	105 kHz 350 kHz	60 V	4 V	Step-Down	1	1	Current Limit Enable Frequency Control Power Good Soft Start Tracking	20-WFQFN Exposed Pad	Transistor Driver	99 %
Analog Devices LTC3891IUDC#TRPBF	Positive	20-QFN (3x4)	Surface Mount	Buck	-40 °C	125 ¯C	535 kHz 835 kHz	105 kHz 350 kHz	60 V	4 V	Step-Down	1	1	Current Limit Enable Frequency Control Power Good Soft Start Tracking	20-WFQFN Exposed Pad	Transistor Driver	99 %
Analog Devices LTC3891HFE#PBF	Positive	20-TSSOP-EP	Surface Mount	Buck	-40 °C	150 °C	535 kHz 835 kHz	105 kHz 350 kHz	60 V	4 V	Step-Down	1	1	Current Limit Enable Frequency Control Power Good Soft Start Tracking		Transistor Driver	99 %	0.173 in 4.4 mm	Exposed Pad	20-TSSOP
Analog Devices LTC3891HUDC#TRPBF	Positive	20-QFN (3x4)	Surface Mount	Buck	-40 °C	150 °C	535 kHz 835 kHz	105 kHz 350 kHz	60 V	4 V	Step-Down	1	1	Current Limit Enable Frequency Control Power Good Soft Start Tracking	20-WFQFN Exposed Pad	Transistor Driver	99 %

Catalog

Low IQ, 60V Synchronous Step-Down Controller

Key Features

• Wide VINRange: 4V to 60V (65V Abs Max)

• Low Operating IQ: 50μA

• Wide Output Voltage Range: 0.8V ≤ VOUT≤ 24V

• RSENSEor 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 VINor EXTVCC

• No Current Foldback During Start-Up

• Small 20-Pin 3mm × 4mm QFN and TSSOP Packages

Description

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.ApplicationsAutomotive Always-On SystemsBattery Powered Digital DevicesDistributed DC Power Systems