Datasheet Linear Technology LTC3854

Manufacturer	Linear Technology
Series	LTC3854

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

Datasheets

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PDF, 547 Kb, Language: en, File uploaded: Sep 23, 2017, Pages: 28
Small Footprint, Wide VIN Range Synchronous Step-Down DC/DC Controller

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Packaging

	LTC3854EDDB#PBF	LTC3854EDDB#TRMPBF	LTC3854EDDB#TRPBF	LTC3854EMSE#PBF	LTC3854EMSE#TRPBF	LTC3854IDDB#PBF	LTC3854IDDB#TRMPBF	LTC3854IDDB#TRPBF	LTC3854IMSE#PBF	LTC3854IMSE#TRPBF
N	1	2	3	4	5	6	7	8	9	10
Package	3x2 DFN-12 Package Outline Drawing	3x2 DFN-12 Package Outline Drawing	3x2 DFN-12 Package Outline Drawing	MS-12E Package Outline Drawing	MS-12E Package Outline Drawing	3x2 DFN-12 Package Outline Drawing	3x2 DFN-12 Package Outline Drawing	3x2 DFN-12 Package Outline Drawing	MS-12E Package Outline Drawing	MS-12E Package Outline Drawing
Package Code	DDB	DDB	DDB	MSE	MSE	DDB	DDB	DDB	MSE	MSE
Package Index	05-08-1723	05-08-1723	05-08-1723	05-08-1666	05-08-1666	05-08-1723	05-08-1723	05-08-1723	05-08-1666	05-08-1666
Pin Count	12	12	12	12	12	12	12	12	12	12

Parametrics

Parameters / Models	LTC3854EDDB#PBF	LTC3854EDDB#TRMPBF	LTC3854EDDB#TRPBF	LTC3854EMSE#PBF	LTC3854EMSE#TRPBF	LTC3854IDDB#PBF	LTC3854IDDB#TRMPBF	LTC3854IDDB#TRPBF	LTC3854IMSE#PBF	LTC3854IMSE#TRPBF
Architecture	Constant Frequency Current Mode	Constant Frequency Current Mode	Constant Frequency Current Mode	Constant Frequency Current Mode	Constant Frequency Current Mode	Constant Frequency Current Mode	Constant Frequency Current Mode	Constant Frequency Current Mode	Constant Frequency Current Mode	Constant Frequency Current Mode
Demo Boards	DC1271A,DC1487A,DC1450A	DC1271A,DC1487A,DC1450A	DC1271A,DC1487A,DC1450A	DC1271A,DC1487A,DC1450A	DC1271A,DC1487A,DC1450A	DC1271A,DC1487A,DC1450A	DC1271A,DC1487A,DC1450A	DC1271A,DC1487A,DC1450A	DC1271A,DC1487A,DC1450A	DC1271A,DC1487A,DC1450A
Design Tools	LTspice File,LTpowerCAD File	LTspice File,LTpowerCAD File	LTspice File,LTpowerCAD File	LTspice File,LTpowerCAD File	LTspice File,LTpowerCAD File	LTspice File,LTpowerCAD File	LTspice File,LTpowerCAD File	LTspice File,LTpowerCAD File	LTspice File,LTpowerCAD File	LTspice File,LTpowerCAD File
Export Control	no	no	no	no	no	no	no	no	no	no
Features	DCR Current Sense	DCR Current Sense	DCR Current Sense	DCR Current Sense	DCR Current Sense	DCR Current Sense	DCR Current Sense	DCR Current Sense	DCR Current Sense	DCR Current Sense
Frequency, kHz	400	400	400	400	400	400	400	400	400	400
Integrated Inductor	no	no	no	no	no	no	no	no	no	no
Ishutdown, µA	10	10	10	10	10	10	10	10	10	10
Isupply, mA	2	2	2	2	2	2	2	2	2	2
Max Phases	1	1	1	1	1	1	1	1	1	1
Monolithic	no	no	no	no	no	no	no	no	no	no
Number of Outputs	1	1	1	1	1	1	1	1	1	1
Operating Temperature Range, °C	0 to 85	0 to 85	0 to 85	0 to 85	0 to 85	-40 to 85	-40 to 85	-40 to 85	-40 to 85	-40 to 85
Output Current, A	25	25	25	25	25	25	25	25	25	25
Polyphase	no	no	no	no	no	no	no	no	no	no
Sense Resistor	Rsense, DCR	Rsense, DCR	Rsense, DCR	Rsense, DCR	Rsense, DCR	Rsense, DCR	Rsense, DCR	Rsense, DCR	Rsense, DCR	Rsense, DCR
Switch Current, A	25	25	25	25	25	25	25	25	25	25
Synchronous	yes	yes	yes	yes	yes	yes	yes	yes	yes	yes
Topology	Buck	Buck	Buck	Buck	Buck	Buck	Buck	Buck	Buck	Buck
Vin Max, V	38	38	38	38	38	38	38	38	38	38
Vin Min, V	4.5	4.5	4.5	4.5	4.5	4.5	4.5	4.5	4.5	4.5
Vout Max, V	5.5	5.5	5.5	5.5	5.5	5.5	5.5	5.5	5.5	5.5
Vout Maximum	5.5V	5.5V	5.5V	5.5V	5.5V	5.5V	5.5V	5.5V	5.5V	5.5V
Vout Min, V	0.8	0.8	0.8	0.8	0.8	0.8	0.8	0.8	0.8	0.8
Vref Accuracy Over Temp, %	1	1	1	1	1	1	1	1	1	1

Eco Plan

	LTC3854EDDB#PBF	LTC3854EDDB#TRMPBF	LTC3854EDDB#TRPBF	LTC3854EMSE#PBF	LTC3854EMSE#TRPBF	LTC3854IDDB#PBF	LTC3854IDDB#TRMPBF	LTC3854IDDB#TRPBF	LTC3854IMSE#PBF	LTC3854IMSE#TRPBF
RoHS	Compliant	Compliant	Compliant	Compliant	Compliant	Compliant	Compliant	Compliant	Compliant	Compliant

Articles

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Step-Down DC/DC Controller in 2mm × 3mm DFN Includes FET Drivers, DCR Sensing and Accepts Inputs to 38V &mdash LT Journal
PDF, 901 Kb, File published: Jul 15, 2011
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Step-Down DC/DC Controller in 2mm Г— 3mm DFN Includes
FET Drivers, DCR Sensing and Accepts Inputs to 38V
Mike Shriver Wide input voltage range and reliability are desirable features in any buck converter. The
LTC3854 delivers these features and more in a 2mm Г— 3mm DFN or MSE package.
This current mode controller with integrated N-channel FET gate drivers can produce
output voltages ranging from 0.8V to 5.5V over an input voltage range of 4.5V to 38V.
SENSING THE CURRENT The LTC3854 employs a fixed frequency
peak current mode topology, which
provides a cycle-by-cycle current limit.
Current can be sensed with discrete
sense resistors in series with the inductor. Alternately, the DC resistance of
the inductor (DCR) can be used to sense
current instead of a sense resistor by
placing an RC filter across the inductor
to recreate the triangular current sense waveform. The advantage of DCR sensing is improved efficiency (thanks to the
elimination of the power losses of the
sense resistor), lower parts count and
lower cost. The disadvantage is a less
accurate current limit due to DCR variations part-to-part and over temperature. but with DCR sensing. The full load efficiency of the circuit with a sense resistor
is 86.9%, while the full load efficiency
increases to 88.7% (see Figure 3) with
DCR sensing. The 400kHz switching frequency provides a good balance between
high efficiency on one hand and a fast …

Model Line

Series: LTC3854 (10)

LTC3854EDDB#PBF LTC3854EDDB#TRMPBF LTC3854EDDB#TRPBF LTC3854EMSE#PBF LTC3854EMSE#TRPBF LTC3854IDDB#PBF LTC3854IDDB#TRMPBF LTC3854IDDB#TRPBF LTC3854IMSE#PBF LTC3854IMSE#TRPBF

Manufacturer's Classification

Power Management > Switching Regulator > Step-Down (Buck) Regulators > External Power Switch Buck Controllers