EG4321 from EG Micro, in a SOP-8. 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	VCC	power_in	Power supply input. Operating range 3.5V to 18V; absolute max 20V. Quiescent current typically 1.6mA.
2	LED_G	output	Green LED (charge-complete) indicator drive. Open-collector sink output; VOL1 typically 0.9V at Isink=10mA.
3	LED_Red	output	Red LED (charge-in-progress) indicator drive. Higher-current sink output; VOL3 typically 0.8V at Isink=200mA.
4	GND	power_in	Ground reference pin.
5	Ifctr	input	Status-switch (turn-light) stage current sensing input. Compared against internal 20mV reference (VFCTR) to trigger charge-complete transition.
6	Iictr	input	Constant-current stage current sensing input. Compared against internal 140mV reference (VICTR) by the current-loop op-amp to regulate charge current.
7	Vctrl	input	Output voltage sensing input. Compared against internal 2.5V reference by the voltage-loop op-amp to regulate constant-voltage stage. Input bias current typ 50nA.
8	Vout	output	Output control pin driving the external regulator. Sink-only (open-collector) output; VOL1 typically 0.9V at Isink=10mA.

Key specifications

Parameter	Value
Manufacturer	EG Micro
Package	SOP-8
Category	PMIC
Pins	8

CAD (KiCad official)

Symbol: EG4321
Footprint: Package_SO:SOIC-8_3.9x4.9mm_P1.27mm
3D model: SOP-8 (KiCad packages3D, STEP)

3D model downloads

Two STEP files. Same geometry, different body top:

File	Size	Use it when
`eg4321.step`	122 KB	You want the bare part, or you mark your own boards.
`eg4321-etched.step`	1.4 MB	You want the part with `EG4321` already on it.

The marking in the etched file is real recessed geometry cut into the solid, not a texture or a decal: 368 faces against 147 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: EG Micro datasheet (14 pp, sha256 38be723226790c61, retrieved 2026-08-17, tier: lcsc)
Datasheet language: Chinese. Pin names, descriptions, and specs on this page were extracted and translated to English by ds2sf; the linked PDF is the manufacturer original.
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