AP3428AKTTR-TP from TECH PUBLIC, in a SOT-23-5. Pinout and pin descriptions extracted from the manufacturer datasheet by ds2sf; symbol, footprint, and 3D from KiCad-official CAD.

Pinout

Pin	Name	Type	Function
1	VIN	power_in	Power supply input, 2.5V to 5.5V operating range (absolute max 6.5V). Must be closely decoupled to GND with a 10µF or greater ceramic capacitor to minimize the CIN/GND loop area.
2	GND	power_in	Analog ground pin. Maximize PCB copper area on this pin for best thermal and noise performance; a ground plane is highly desirable.
3	EN	input	Chip enable pin. Drive above VIH=1.5V to turn on the regulator; drive below VIL=0.4V to turn it off. Do not leave floating; input current ~1µA.
4	FB	input	Output feedback pin. Connect to the center of the output resistor divider (R1/R2) to program Vout = 0.6V * (1 + R1/R2). VREF = 0.6V typical (0.588-0.612V).
5	LX	output	Power switch output - switch node connecting to the external inductor. This pin ties to the drains of the internal P-ch and N-ch MOSFETs; keep PCB copper area on LX minimized to reduce switching noise.

Key specifications

Parameter	Value
Manufacturer	TECH PUBLIC
Package	SOT-23-5
Category	PMIC
Pins	5

Ordering variants

Same part, different packaging or reel option.

AP3428AKTTR-TP

CAD (KiCad official)

Symbol: AP3428AKTTR-TP
Footprint: Package_TO_SOT_SMD:SOT-23-5
3D model: SOT-23-5 (KiCad packages3D, STEP)

Provenance

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

Datasheet: TECH PUBLIC datasheet (7 pp, sha256 0f5ba041aa89d6c8, retrieved 2026-08-17, tier: lcsc)
Extractor: ds2sf (Claude). Every pin and dimension is cited to a datasheet page; it refuses to fabricate.
CAD: KiCad official libraries (CC-BY-SA 4.0).

Datasheet PDF