LTC3854 - Small Footprint, Wide VIN Range Synchronous Step-Down DC/DC Controller

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.

Features

Wide Operating VIN Range: 4.5V to 38V
RSENSE or 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

Typical Application

Applications

Automotive Systems
Telecom Systems
Industrial Equipment
Distributed DC Power Systems

Packaging

Order Information

Part Number	Package	Temp	Price(1-99)	Price (1k)*
LTC3854EDDB#PBF	3x2 DFN-12	E	$2.39
LTC3854EDDB#TRMPBF	3x2 DFN-12	E	$2.36	$1.70
LTC3854EDDB#TRPBF	3x2 DFN-12	E	$2.36	$1.65
LTC3854EMSE#PBF	MS-12E	E	$2.36	$1.65
LTC3854EMSE#TRPBF	MS-12E	E		$1.71
LTC3854IDDB#PBF	3x2 DFN-12	I	$2.69
LTC3854IDDB#TRMPBF	3x2 DFN-12	I	$2.69	$1.93
LTC3854IDDB#TRPBF	3x2 DFN-12	I	$2.69	$1.88
LTC3854IMSE#PBF	MS-12E	I	$2.69	$1.88
LTC3854IMSE#TRPBF	MS-12E	I		$1.94

Demo Boards

Part Number	Description	Price
DC1271A	LTC3854EDDB Demo Board \| 4.5V ≤ VIN ≤ 14V, VOUT = 1.5V @ 15A	$100.00
DC1450A	LTC3854EDDB Demo Board \| 4.5V ≤ VIN ≤ 26V, VOUT = 2.5V @ 5A	$100.00
DC1487A	LTC3854EMSE Demo Board \| 4.5V ≤ VIN ≤ 34V, VOUT = 2.5V @ 12A	$100.00