RY3420 from RYCHIP, in a SOT-23-5. Pinout and pin descriptions extracted from the datasheet by ds2sf; symbol, footprint, and 3D from KiCad-official CAD.

Pinout

Pin	Name	Type	Function
1	EN	input	Chip Enable. Drive above 1.5V (typ 1.15V rising threshold, 140mV hysteresis) to turn the regulator on; drive below 0.3V to shut it down. Must not be left floating.
2	GND	power_in	Ground return for the device. Should be tied to a large copper pour for thermal dissipation.
3	SW	power_out	Switch node output. Connected to the drains of the internal P-ch and N-ch power MOSFETs and drives the external inductor. Rated for 3A peak sink/source current.
4	IN	power_in	Power supply input, 2.5V to 5.5V operating range (6.0V absolute max). Must be closely decoupled to GND with a 10µF or greater ceramic capacitor.
5	FB	input	Output voltage feedback input. Connect to the midpoint of an external resistor divider from VOUT to GND; regulates to the internal 0.600V reference (VOUT = 0.6V × (R1+R2)/R2).

Key specifications

Parameter	Value
Manufacturer	RYCHIP
Package	SOT-23-5
Category	PMIC
Pins	5

Ordering variants

Same part, different packaging or reel option.

RY3420ADYLL

CAD (KiCad official)

Symbol: RY3420
Footprint: Package_TO_SOT_SMD:SOT-23-5
3D model: SOT-23-5 (KiCad packages3D, STEP)

3D model downloads

Two STEP files. Same geometry, different body top:

File	Size	Use it when
`ry3420.step`	85 KB	You want the bare part, or you mark your own boards.
`ry3420-etched.step`	1.4 MB	You want the part with `RY3420` already on it.

The marking in the etched file is real recessed geometry cut into the solid, not a texture or a decal: 350 faces against 102 in the bare model. It survives export, section views, and rendering in any CAD tool, and it drops straight into KiCad or Fusion with no extra setup.

Provenance

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

Datasheet: RYCHIP datasheet (9 pp, sha256 e2817c95aff7799d, 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