LT3741EUF#TRPBF from Analog Devices, in a QFN-20-EP(4x4). 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	EN/UVLO	input	Enable pin that turns on the internal bias at a 1.55V falling threshold with 130mV hysteresis, has no pull-up or pull-down, and full shutdown occurs at about 0.5V; absolute maximum voltage is 6V.
2	VREF	power_in	Buffered 2V reference that can supply up to 500µA, current limited to 1mA, and is rated to 3V absolute maximum.
3	CTRL2	input	Thermal control input used to reduce the regulated current level, with absolute maximum voltage of 3V.
4	GND	power_in	Ground pin that must be connected to the system ground.
5	CTRL1	input	Sets the high-level regulated output current and overcurrent point, with a control range of 0V to 1.5V that is internally clamped to 1.5V.
6	SS	passive	Soft-start pin with an external capacitor to ground that is charged with an 11µA source to limit the regulated current during start-up; absolute maximum voltage is 6V.
7	FB	input	Feedback pin for voltage regulation with a 1.21V feedback voltage, where overvoltage above 1.5V prevents switching for 13µs; absolute maximum voltage is 3V.
8	SENSE+	input	Inverting input of the average current-mode error amplifier, connected to the external sense resistor RS; absolute maximum voltage is 40V.
9	SENSE-	input	Non-inverting input of the average current-mode error amplifier, from which the reference current flows to the output side of RS; absolute maximum voltage is 40V.
10	VC	passive	Compensation pin for the average current loop, with typical values of 20k to 50k for the resistor and 2nF to 5nF for the capacitor; absolute maximum voltage is 3V.
11	GND	power_in	Ground pin that must be connected to the system ground.
12	RT	passive	Resistor to ground sets the switching frequency from 200kHz to 1MHz, the pin is current limited to 60µA, and it must not be left open.
13	SYNC	input	Frequency synchronization pin where RT should be set 20% slower than the SYNC pulse frequency; it should be grounded when not in use and has a 6V absolute maximum.
14	GND	power_in	Ground pin that must be connected to the system ground.
15	HG	output	Gate drive for the high-side external power FET with 2.3Ω pull-up and 1.3Ω pull-down impedance.
16	SW	passive	Lower rail for the floating high-side driver that connects the two power FETs and the inductor; absolute maximum voltage is 40V.
17	CBOOT	power_out	Floating 5V regulated supply for the high-side FET driver, charged through an external Schottky diode from VCC_INT; absolute maximum voltage is 46V.
18	LG	output	Gate drive for the low-side external power FET with 2.3Ω pull-up and 1.0Ω pull-down impedance.
19	VCC_INT	power_out	Regulated 5V output for charging the CBOOT capacitor and powering digital and switching circuits, current limited to 50mA; tie to the rail when VIN is below 6V; absolute maximum voltage is 6V.
20	VIN	power_in	Input supply pin for the 6V to 36V input range, which must be locally bypassed with a 4.7µF low-ESR capacitor to ground; absolute maximum voltage is 40V.
21	GND	power_in	Exposed pad, internally GND, that must be soldered to the PCB.

Key specifications

Parameter	Value
Manufacturer	Analog Devices
Package	QFN-20-EP(4x4)
Category	Power Management ICs
Pins	21

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 Range		6		36	V		3
VIN Pin Quiescent Current, Non-Switching Operation			1.8	2.5	mA	Not Switching	3
VIN Pin Quiescent Current, Shutdown Mode			0.1	1	µA	VEN/UVLO = 0V, RT = 40kΩ	3
EN/UVLO Pin Falling Threshold		1.49	1.55	1.61	V		3
CTRL1 Pin Control Range		0		1.5	V		3
Reference Voltage (VREF Pin)		1.94	2	2.06	V		3
Full Range SENSE+ to SENSE-		48	51	54	mV	VCTRL1 = 1.5V	3
Internal VCC Regulator Regulation Voltage (VCC_INT Pin)		4.7	5	5.2	V		3
Switching Frequency	fSW	900	1000	1070	kHz	RT = 40kΩ	3
Switching Frequency	fSW	185	200	233	kHz	RT = 200kΩ	3
Feedback Regulation Voltage		1.192	1.21	1.228	V	CTRL1 = 1.5V, ISENSE- = 23µA, VSENSE+ = 2V	3
Current Control Loop gm Amp Offset Voltage		-3	0	3	mV	VCM = 4V	4
Current Control Loop gm Amp Transconductance	gm	375	475	625	µA/V		4
Operating Temperature Range (LT3741EUF#TRPBF order grade E)		-40		125	°C	Order information, E grade	2
VIN Voltage				40	V		2
EN/UVLO Voltage				6	V		2
VREF Voltage				3	V		2
CTRL1 and CTRL2 Voltage				3	V		2
SENSE+ Voltage				40	V		2
SENSE- Voltage				40	V		2
VC Voltage				3	V		2
SW Voltage				40	V		2
RT Voltage				3	V		2
FB Voltage				3	V		2
SS Voltage				6	V		2
VCC_INT Voltage				6	V		2
SYNC Voltage				6	V		2
Storage Temperature Range		-65		150	°C		2
Thermal Resistance Junction-to-Ambient (QFN package)	θJA		37		°C/W	UF package, 20-lead 4mm × 4mm QFN	2
Maximum Junction Temperature (QFN package)	TJMAX			125	°C	UF package, 20-lead 4mm × 4mm QFN	2

CAD (KiCad official)

Symbol: LT3741EUF#TRPBF
Footprint: Package_DFN_QFN:QFN-20-1EP_4x4mm_P0.5mm_EP2.5x2.5mm
3D model: QFN-20-EP(4x4) (KiCad packages3D, STEP)
3D model files: lt3741euf-trpbf-etched.step / lt3741euf-trpbf-etched.glb carry the MPN laser-etched on the die in a toggleable Adom.LaserEtch group (Fusion-ready); lt3741euf-trpbf.step / lt3741euf-trpbf.glb are the bare package body.

Provenance

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

Datasheet: Analog Devices datasheet (24 pp, sha256 ffd25fe12b4612d5, retrieved 2026-10-30, 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

LT3741EUF#TRPBF

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3D Model

Symbol & Footprint

Schematic Symbol

PCB Footprint

Datasheet

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