LT3971EMSE-5#PBF from Analog Devices, in a MSOP-10-EP. Pinout and pin descriptions extracted from the manufacturer datasheet (extract_pins, cross-checked by a second model); symbol, footprint, and 3D from KiCad-official CAD.

Pinout

Pin	Name	Type	Function
1	BD	input	Anode of the internal boost diode, normally connected to the output; boost diode current is limited to 1A and BD voltage to 30V.
2	BOOST	passive	Provides a drive voltage higher than the input voltage to the internal bipolar NPN power switch; absolute maximum 55V, and no more than 30V above SW.
3	SW	output	Output of the internal power switch; connect to the inductor, catch diode, and boost capacitor.
4	VIN	power_in	Supplies current to the internal circuitry and power switch, must be locally bypassed; input range 4.3V to 38V.
5	EN	input	Part is in shutdown when low and active when high, with a 1.005V rising and 0.975V falling threshold accurate only when VIN is above 4.3V; tie to VIN if shutdown is not used.
6	VOUT	input	The LT3971-5 regulates this pin to 5V; it connects to the internal 10MΩ feedback divider that programs the fixed output voltage.
7	SS	passive	Soft-start capacitor to ground ramps up the peak current limit on start-up; it is discharged only when EN is low, float to disable soft-start, and add a 100k series resistor for VIN above 25V.
8	RT	passive	A resistor from RT to ground sets the switching frequency (200kHz to 2MHz).
9	PG	output	Open-drain power good output from an internal comparator that stays low until the output is within 9% of final regulation, valid when enabled and VIN is above 4.3V.
10	SYNC	input	External clock synchronization input from 250kHz to 2MHz; ground for low ripple Burst Mode operation, while a clock source causes pulse-skipping with quiescent current rising to 1.5mA.
11	GND	power_in	Ground via the exposed pad (pin 11), which must be soldered to the PCB.

Key specifications

Parameter	Value
Manufacturer	Analog Devices
Package	MSOP-10-EP
Category	Power Management ICs
Pins	11

Electrical characteristics

Limits as printed in the datasheet (page.json metadata.characteristics carries them as data).

Parameter	Symbol	Min	Typ	Max	Unit	Conditions	Page
LT3971-5 Output Voltage (25°C)	VOUT	4.93	5	5.07	V	TA = 25°C	3
LT3971-5 Output Voltage (full temp range)	VOUT	4.89	5	5.11	V	over full operating temperature range	3
Minimum Input Voltage	VIN(MIN)		4	4.3	V	Note 4; full temp range	3
Quiescent Current from VIN, VEN Low	IQ		0.7		µA	VEN Low	3
Quiescent Current from VIN, VEN High, VSYNC Low	IQ		1.7		µA	VEN High, VSYNC Low	3
Quiescent Current from VIN, VEN High, VSYNC Low (full temp)	IQ		1.2	4.5	µA	VEN High, VSYNC Low, full temp range	3
Internal Feedback Resistor Divider			10		MΩ	LT3971-X	3
FB Voltage Line Regulation			0.0002	0.01	%/V	4.3V < VIN < 38V (Note 4)	3
Switching Frequency	fSW	1.6	2	2.4	MHz	RT = 11k	3
Switching Frequency	fSW	0.8	1	1.2	MHz	RT = 35.7k	3
Switching Frequency	fSW	160	200	240	kHz	RT = 255k	3
Minimum Switch On Time	tON(MIN)		80		ns		3
Minimum Switch Off Time	tOFF(MIN)		110	150	ns		3
Switch Current Limit	ILIM	1.8	2.4	3	A		3
Switch VCESAT	VCESAT		330		mV	ISW = 1A	3
Switch Leakage Current			0.02	1	µA		3
Boost Schottky Forward Voltage			770		mV	ISH = 100mA	3
Boost Schottky Reverse Leakage			0.02	1	µA	VREVERSE = 12V	3
Minimum Boost Voltage			1.4	1.8	V	VIN = 5V (Note 3)	3
BOOST Pin Current			20	28	mA	ISW = 1A, VBOOST = 15V	3
EN Voltage Threshold		0.95	1.01	1.07	V	EN Rising	3
EN Voltage Hysteresis			30		mV		3
EN Pin Current			0.2	20	nA		3
LT3971-X PG Threshold Offset from VOUT		5.5	9	12.5	%	VOUT Rising	3
LT3971-X PG Hysteresis			1.3		%		3
PG Leakage			0.02	1	µA	VPG = 3V	4
PG Sink Current		300	570		µA	VPG = 0.4V	4
SYNC Threshold		0.6	0.8	1	V		4
SYNC Pin Current			0.1		nA		4
SS Source Current		0.6	1	1.6	µA	VSS = 1V	4
VIN, EN Voltage				38	V		2
BOOST Pin Above SW Pin				30	V		2
FB, VOUT, RT, SYNC, SS Voltage				6	V		2
PG, BD Voltage				30	V		2
Boost Diode Current				1	A		2
Operating Junction Temperature Range (LT3971E)		-40		125	°C	Note 2	2
Storage Temperature Range		-65		150	°C		2
Thermal Resistance Junction to Ambient	θJA		45		°C	10-lead MSE package	2
Thermal Resistance Junction to Case	θJC		10		°C/W	10-lead MSE package	2

CAD (KiCad official)

Symbol: LT3971EMSE-5#PBF
Footprint: Package_SO:MSOP-10-1EP_3x3mm_P0.5mm_EP1.68x1.88mm
3D model: MSOP-10-EP (KiCad packages3D, STEP)
3D model files: lt3971emse-5-pbf-etched.step / lt3971emse-5-pbf-etched.glb carry the MPN laser-etched on the die in a toggleable Adom.LaserEtch group (Fusion-ready); lt3971emse-5-pbf.step / lt3971emse-5-pbf.glb are the bare package body.

Provenance

Data extracted from the manufacturer datasheet, not a distributor listing:

Datasheet: Analog Devices datasheet (28 pp, sha256 cf769206b11377dd, retrieved 2026-10-31, tier: manufacturer)
Extractor: parts-factory 2.0.0 / extract_pins 0.3, primary claude-sonnet-5-5 (text), consensus claude-sonnet-5-5 (agreed), guards: pin_guards 0.1: passed. Pins are checked against the footprint pad set and their cited datasheet pages before publish.
CAD: KiCad official libraries (CC-BY-SA 4.0).

Datasheet PDF

LT3971EMSE-5#PBF

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3D Model

Symbol & Footprint

Schematic Symbol

PCB Footprint

Datasheet

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