LT1521CS8-5#TRPBF from Analog Devices, in a SO-8. 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	OUT	power_out	The output pin supplies power to the load and requires a minimum output capacitor of 1.5µF to prevent oscillations.
2	SENSE	input	For the LT1521-5 fixed-voltage version, the sense pin is the error amplifier input, with a bias current of 5µA at nominal output and internal clamping to -0.6V.
3	GND	power_in	Ground pin; the S8 package thermal note identifies pins 3, 6 and 7 as ground.
4	NC	unconnected	No internal connection on this package; it is not used by the device function.
5	SHDN	input	Active-low shutdown input that turns the output off when pulled low, with internal clamps at 7V and -0.6V and pull-up current limited to a maximum of 5mA.
6	GND	power_in	Ground pin; the S8 package thermal note identifies pins 3, 6 and 7 as ground.
7	GND	power_in	Ground pin; the S8 package thermal note identifies pins 3, 6 and 7 as ground.
8	IN	power_in	Supply input that withstands reverse voltages of 20V and should be bypassed with 1µF to 10µF when the device is more than six inches from the main input filter capacitor.

Key specifications

Parameter	Value
Manufacturer	Analog Devices
Package	SO-8
Category	Power Management ICs
Pins	8

Electrical characteristics

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

Parameter	Min	Typ	Max	Unit	Conditions	Page
Regulated Output Voltage	4.925	5	5.075	V	LT1521-5 VIN = 5.5V, IOUT = 1mA, TJ = 25°C	3
Regulated Output Voltage	4.85	5	5.15	V	LT1521-5 6V < VIN < 20V, 1mA < IOUT < 300mA (full operating temperature range)	3
Shutdown Threshold	1.2		2.8	V	VOUT = Off to On (full operating temperature range)	3
Shutdown Threshold	0.25		0.75	V	VOUT = On to Off (full operating temperature range)	3
Ripple Rejection	50	58		dB	VIN - VOUT = 1V(Avg), VRIPPLE = 0.5VP-P, fRIPPLE = 120Hz, ILOAD = 150mA	3
Current Limit		400	800	mA	VIN - VOUT = 7V, TJ = 25°C	3
Current Limit	320		400	mA	VIN = VOUT (NOMINAL) + 1.5V, ∆VOUT = -0.1V (full operating temperature range)	3
Shutdown Pin Current		2	5	µA	VSHDN = 0V (full operating temperature range)	3
Quiescent Current in Shutdown		6	12	µA	VIN = VOUT (NOMINAL) + 1V, VSHDN = 0V (full operating temperature range)	3
Reverse Output Current		5	10	µA	LT1521-5 VOUT = 5V, VIN < 5V, TJ = 25°C	4
Input Reverse Leakage Current			1	mA	VIN = -20V, VOUT = 0V (full operating temperature range)	4
Line Regulation		1.5	20	mV	LT1521-5 ∆VIN = 5.5 to 20V, IOUT = 1mA (full operating temperature range)	3
Load Regulation		-25	-45	mV	LT1521-5 ∆ILOAD = 1mA to 300mA, TJ ≤ 25°C	3
Load Regulation		-25	-75	mV	LT1521-5 ∆ILOAD = 1mA to 300mA, TJ > 25°C	3
Dropout Voltage		130	170	mV	ILOAD = 1mA, TJ = 25°C	3
Dropout Voltage			250	mV	ILOAD = 1mA (full operating temperature range)	3
Dropout Voltage		290	350	mV	ILOAD = 50mA, TJ = 25°C	3
Dropout Voltage			450	mV	ILOAD = 50mA (full operating temperature range)	3
Dropout Voltage		350	420	mV	ILOAD = 100mA, TJ = 25°C	3
Dropout Voltage			550	mV	ILOAD = 100mA (full operating temperature range)	3
Dropout Voltage		400	470	mV	ILOAD = 150mA, TJ = 25°C	3
Dropout Voltage			600	mV	ILOAD = 150mA (full operating temperature range)	3
Dropout Voltage		500	600	mV	ILOAD = 300mA, TJ = 25°C	3
Dropout Voltage			750	mV	ILOAD = 300mA (full operating temperature range)	3
Ground Pin Current		12	25	µA	ILOAD = 0mA (full operating temperature range)	3
Ground Pin Current		65	100	µA	ILOAD = 1mA (full operating temperature range)	3
Ground Pin Current		300	450	µA	ILOAD = 10mA (full operating temperature range)	3
Ground Pin Current		0.8	1.5	mA	ILOAD = 50mA (full operating temperature range)	3
Ground Pin Current		1.4	2.5	mA	ILOAD = 100mA (full operating temperature range)	3
Ground Pin Current		2.2	4	mA	ILOAD = 150mA (full operating temperature range)	3
Ground Pin Current		6.5	12	mA	ILOAD = 300mA (full operating temperature range)	3
Input Voltage	-20		20	V	Input Voltage (applications above 20V: contact factory)	2
Output Pin Reverse Current			10	mA		2
Shutdown Pin Input Voltage	-0.6		6.5	V	Note 1	2
Shutdown Pin Input Current			5	mA	Note 1	2
Storage Temperature Range	-65		150	°C		2
Operating Junction Temperature Range	0		125	°C	Commercial (Note 2)	2
Lead Temperature			300	°C	Soldering, 10 sec	2
Thermal Resistance Junction-to-Ambient		60		°C/W	S8 package, copper area topside 2500mm2, backside 2500mm2, board area 2500mm2	10
Thermal Resistance Junction-to-Ambient		68		°C/W	S8 package, copper area topside 225mm2, backside 2500mm2, board area 2500mm2	10
Thermal Resistance Junction-to-Ambient		74		°C/W	S8 package, copper area topside 100mm2, backside 2500mm2, board area 2500mm2	10

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		3/32" FR-4 board with one ounce copper. All NC leads were	10

CAD (KiCad official)

Symbol: LT1521CS8-5#TRPBF
Footprint: Package_SO:SOIC-8_3.9x4.9mm_P1.27mm
3D model: SO-8 (KiCad packages3D, STEP)
3D model files: lt1521cs8-5-trpbf-etched.step / lt1521cs8-5-trpbf-etched.glb carry the MPN laser-etched on the die in a toggleable Adom.LaserEtch group (Fusion-ready); lt1521cs8-5-trpbf.step / lt1521cs8-5-trpbf.glb are the bare package body.

Provenance

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

Datasheet: Analog Devices datasheet (16 pp, sha256 a580c39ec72785d9, retrieved 2026-11-02, 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

LT1521CS8-5#TRPBF

Verified LT1521CS8-5#TRPBF

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3D Model

Symbol & Footprint

Schematic Symbol

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Datasheet

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