LM3671MFX-ADJ from Texas Instruments, in a SOT-23-5. 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	VIN	power_in	Power supply input that connects to the input filter capacitor, with the device rated for a 2.7 V to 5.5 V input range.
2	GND	power_in	Ground pin for the converter.
3	EN	input	Digital enable pin: the device is in shutdown mode when the voltage is below 0.4 V and enabled above 1 V, and this pin must not be left floating.
4	FB	input	Feedback analog input that connects directly to the output filter capacitor for fixed versions, while the adjustable version requires external resistor dividers since its internal dividers are disabled.
5	SW	output	Switching node connection to the internal PFET switch and NFET synchronous rectifier.

Key specifications

Parameter	Value
Manufacturer	Texas Instruments
Package	SOT-23-5
Category	Power Management (PMIC)
Pins	5

Electrical characteristics

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

Parameter	Symbol	Min	Typ	Max	Unit	Conditions	Page
Input voltage	VIN	2.7		5.5	V	−40°C to 125°C, see(4)	6
Feedback voltage (ADJ) MF PWM mode	VFB	-4		4	%	MF, PWM mode, −40°C to 125°C	6
Shutdown supply current	ISHDN			1	µA	EN = 0 V, −40°C to 125°C	6
DC bias current into VIN	IQ		16	35	µA	No load, device is not switching (FB forced higher than programmed output voltage), −40°C to 125°C	6
Pin-pin resistance for PFET	RDSON (P)		380	500	mΩ	VIN = VGS = 3.6 V	6
Pin-pin resistance for NFET	RDSON (N)		250	400	mΩ	VIN = VGS = 3.6 V	6
Switch peak current limit	ILIM	830	1020	1150	mA	Open loop, −40°C to 125°C (typ at 25°C open loop)	6
Logic high input	VIH	1			V	−40°C to 125°C	6
Logic low input	VIL			0.4	V	−40°C to 125°C	6
Enable (EN) input current	IEN		0.01	1	µA	−40°C to 125°C	6
Internal oscillator frequency	ƒOSC	1.6	2	2.6	MHz	PWM Mode, −40°C to 125°C (typ at PWM mode)	6
VIN pin voltage to GND	VIN	-0.2		6	V	Absolute maximum, voltage to GND	4
FB, SW, EN pins voltage	FB, SW, EN	-0.2			V	GND − 0.2 to VIN + 0.2 V as printed	4
Junction temperature, TJ-MAX	TJ-MAX			125	°C	Absolute maximum	4
Maximum lead temperature (soldering, 10 sec.)				260	°C	Soldering, 10 sec.	4
Storage temperature	Tstg	-65		150	°C		4
Recommended load current		0		600	mA		5
Junction temperature, TJ	TJ	-40		125	°C		5
Ambient temperature, TA	TA	-40		85	°C		5
Junction-to-ambient thermal resistance (DBV SOT-23)	RθJA		165.7		°C/W	DBV (SOT-23), 5 pins	5
Junction-to-board thermal resistance (DBV SOT-23)	RθJB		26.8		°C/W	DBV (SOT-23), 5 pins	5

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
contacts	copper		3. Connect the ground pins of the LM3671 and filter capacitors together using generous component-side copper fill as a pseudo-ground plane. Then, connect this to the ground-plane (if one is used) with	21

CAD (KiCad official)

Symbol: LM3671MFX-ADJ
Footprint: Package_TO_SOT_SMD:SOT-23-5
3D model: SOT-23-5 (KiCad packages3D, STEP)
3D model files: lm3671mfx-adj-etched.step / lm3671mfx-adj-etched.glb carry the MPN laser-etched on the die in a toggleable Adom.LaserEtch group (Fusion-ready); lm3671mfx-adj.step / lm3671mfx-adj.glb are the bare package body.

Provenance

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

Datasheet: Texas Instruments datasheet (38 pp, sha256 5fddbe8ad486a080, retrieved 2026-11-06, tier: manufacturer)
Extractor: parts-factory 2.0.0 / extract_pins 0.3, primary claude-haiku-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

LM3671MFX-ADJ

Verified LM3671MFX-ADJ

Verification log 1 record

3D Model

Symbol & Footprint

Schematic Symbol

PCB Footprint

Datasheet

README