LT3973EMSE#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	FB	input	Feedback pin regulated to 1.21V; connect the feedback resistor divider tap to this pin (LT3973 adjustable version).
2	OUT	input	Regulates VIN to VOUT voltage in dropout and supplies current to charge the boost capacitor; connect to the output, or tie to GND if programmed output is greater than 14V.
3	EN/UVLO	input	Part is in shutdown when low and active when high, with a 1.19V rising threshold and 30mV hysteresis; tie to VIN if unused, and ground it if VIN is below 4.2V to shut down.
4	VIN	power_in	Supplies current to the internal circuitry and internal power switch (4.2V to 42V operating); must be locally bypassed.
5	GND	power_in	Ground pin; the exposed pad (pin 11) is also ground and must be soldered to the PCB.
6	SW	output	Output of the internal power switch; connect to the inductor.
7	BOOST	passive	Provides a drive voltage higher than the input voltage to the internal bipolar NPN power switch.
8	BD	input	Anode of the boost diode; also supplies current to the internal regulator when BD is above 3.2V.
9	PG	output	Open-drain output of an internal comparator that stays low until FB is within 10% of final regulation voltage; valid when VIN is above 4.2V and EN/UVLO is high.
10	RT	passive	A resistor from RT to ground sets the switching frequency (200kHz to 2.2MHz).
11	GND	power_in	Exposed pad is ground and must be soldered to the PCB.

Key specifications

Parameter	Value
Manufacturer	Analog Devices
Package	MSOP-10-EP
Category	Interface 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
Minimum Input Voltage			3.8	4.2	V	Note 3, over full temp range	3
Quiescent Current from VIN, EN/UVLO Low	IQ		0.75	1.3	µA	VEN/UVLO Low	3
Quiescent Current from VIN, EN/UVLO High	IQ		1.8	2.8	µA	VEN/UVLO High	3
Quiescent Current from VIN, EN/UVLO High, -40°C to 125°C	IQ			6	µA	VEN/UVLO High, -40°C to 125°C	3
LT3973 Feedback Voltage	VFB	1.195	1.21	1.225	V	TA = 25°C	3
LT3973 Feedback Voltage (full temp range)	VFB	1.185	1.21	1.235	V	over full operating temperature range	3
LT3973 FB Pin Bias Current			0.1	20	nA	VFB = 1.21V	3
FB/Output Voltage Line Regulation			0.0002	0.01	%/V	4.2V < VIN < 40V	3
Switching Frequency	fSW	1.72	2.15	2.58	MHz	RT = 41.2k, VIN = 6V	3
Switching Frequency	fSW	632	790	948	kHz	RT = 158k, VIN = 6V	3
Switching Frequency	fSW	156	195	234	kHz	RT = 768k, VIN = 6V	3
Switch Current Limit		1.237	1.65	1.98	A	VIN = 5V, VFB = 0V	3
Catch Schottky Current Limit		0.92	1.15	1.44	A	VIN = 5V	3
Switch Leakage Current			0.05	2	µA		3
Catch Schottky Reverse Leakage			0.05	2	µA	VSW = 12V	3
Boost Schottky Reverse Leakage			0.02	2	µA	VREVERSE = 12V	3
Minimum Boost Voltage			1.4	1.8	V	VIN = 5V, Note 4	3
BOOST Pin Current			10	13	mA	ISW = 500mA, VBOOST = 15V	3
Dropout Comparator Threshold (VIN - OUT)		400	490	580	mV	Falling, VIN = 5V	3
EN/UVLO Pin Current			1	30	nA	VEN/UVLO = 12V	4
EN/UVLO Voltage Threshold Falling		1.09	1.16	1.23	V	EN/UVLO Falling, VIN ≥ 4.2V	4
EN/UVLO Voltage Threshold Rising		1.12	1.19	1.28	V	EN/UVLO Rising, VIN ≥ 4.2V	4
EN/UVLO Voltage Hysteresis			30	45	mV		4
PG Threshold Offset from Feedback Voltage		6.5	10	13.5	%	VFB Rising	4
PG Leakage			0.01	1	µA	VPG = 3V	4
PG Sink Current		220	350		µA	VPG = 0.4V	4
Minimum Switch Off-Time			130	180	ns	VIN = 10V, Note 5	4
BOOST Pin Above SW Pin				25	V		2
FB/VOUT, RT, PG Voltage				6	V		2
BD Voltage				25	V		2
Operating Junction Temperature Range (LT3973E)	TJ	-40		125	°C	LT3973E	2
Storage Temperature Range		-65		150	°C		2
Thermal Resistance Junction-to-Ambient	θJA		45		°C/W	MSE package	2
Thermal Resistance Junction-to-Case	θJC		10		°C/W	MSE package	2

Materials and finish

As the datasheet states them (page.json metadata.appearance; the 3D model's colours follow it).

Part	Material	Colour / plating	Datasheet says	Page
housing	ABS		LT3973HMSE-5#PBF LT3973HMSE-5#TRPBF LTGGD 10-Lead Plastic MSOP -40°C to 150°C ABSOLUTE MAXIMUM RATINGS	2

CAD (KiCad official)

Symbol: LT3973EMSE#PBF
Footprint: Package_SO:MSOP-10-1EP_3x3mm_P0.5mm_EP1.68x1.88mm
3D model: MSOP-10-EP (KiCad packages3D, STEP)
3D model files: lt3973emse-pbf-etched.step / lt3973emse-pbf-etched.glb carry the MPN laser-etched on the die in a toggleable Adom.LaserEtch group (Fusion-ready); lt3973emse-pbf.step / lt3973emse-pbf.glb are the bare package body.

Provenance

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

Datasheet: Analog Devices datasheet (24 pp, sha256 8b84083bfbac6278, 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).

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LT3973EMSE#PBF

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