LTC3854 Series

Small Footprint, Wide VINRange Synchronous Step-Down DC/DC Controller

Catalog

Small Footprint, Wide VINRange Synchronous Step-Down DC/DC Controller

Part	Number of Outputs	Output Phases	Frequency - Switching	Mounting Type	Operating Temperature [Max]	Operating Temperature [Min]	Control Features	Output Type	Duty Cycle (Max) [Max]	Supplier Device Package	Function	Topology	Output Configuration	Voltage - Supply (Vcc/Vdd) [Max]	Voltage - Supply (Vcc/Vdd) [Min]	Package / Case	Package / Case
Analog Devices LTC3854EDDB#TRMPBF	1	1	400 kHz	Surface Mount	85 °C	-40 °C	Enable Soft Start	Transistor Driver	98 %	12-DFN (3x2)	Step-Down	Buck	Positive	38 V	4.5 V	12-WFDFN Exposed Pad
Analog Devices LTC3854EMSE#PBF	1	1	400 kHz	Surface Mount	85 °C	-40 °C	Enable Soft Start	Transistor Driver	98 %	12-MSOP-EP	Step-Down	Buck	Positive	38 V	4.5 V	12-TSSOP Exposed Pad	0.118 in 3 mm
Analog Devices LTC3854IMSE#PBF	1	1	400 kHz	Surface Mount	85 °C	-40 °C	Enable Soft Start	Transistor Driver	98 %	12-MSOP-EP	Step-Down	Buck	Positive	38 V	4.5 V	12-TSSOP Exposed Pad	0.118 in 3 mm

Catalog

Small Footprint, Wide VINRange Synchronous Step-Down DC/DC Controller

Key Features

• Wide Operating VINRange: 4.5V to 38V

• RSENSEor 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 COUT

• Low Shutdown IQ: 15μA

• Tiny Thermally Enhanced 12-Pin 2mm × 3mm DFN and MSOP Packages

Description

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.ApplicationsAutomotive SystemsTelecom SystemsIndustrial EquipmentDistributed DC Power Systems