IP5209T from INJOINIC, in a QFN-24-EP(4x4). 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	L2/SDA	bidirectional	Battery-level LED driver pin L2; also acts as the I2C SDA data line when I2C function is enabled.
2	L3	output	Battery-level indicator LED driver pin L3. Drives the 3rd LED in multi-LED fuel-gauge display modes.
3	VREG	power_out	Internal 3.1V LDO regulator output. Sourcing capability ~5 mA; no output in sleep state. Used as internal supply and reference; also selects VTHS high-platform battery voltage when tied to VTHS.
4	VTHS	input	Battery platform-select input. Tie to VREG for high-platform 3.7V battery; tie to GND for low-platform 3.6V battery.
5	RSET	input	Battery internal-resistance compensation setting via external resistor to GND. Tunes fuel-gauge curve (e.g. 10K=45mΩ, 43K=67.5mΩ, 120K=112.5mΩ, 200K=90mΩ, NC=22.5mΩ).
6	NTC	input	Battery temperature sense input for external NTC thermistor. Sources 20 µA; thresholds VH=0.43V (>55°C), VM=0.58V (>45°C, half charge current), VL=1.44V (<-10°C, stop charge/discharge). Tie to GND if unused.
7	AGND	power_in	Analog ground reference for the control/analog blocks.
8	KEY	input	Push-button input to GND. Short press (60ms-2s) enables battery-display LED and 5V boost output; long press (>2s) toggles flashlight LED; double-tap within 1s turns off boost, LED display and flashlight.
9	VBAT	power_in	Boost converter input; connect to Li-ion battery positive terminal. Operating range 3.0-4.4V.
10	NC	unconnected	No connect. Leave floating.
11	ICHG	input	Charge current program pin. External resistor to GND sets charge current per ICHG = 1.2V/R × 10000 (e.g. 120K=1A, 100K=1.2A, 82K=1.5A, 51K=2.4A, NC=default 1.9A).
12	PGND	power_in	Power ground for the switching power stage.
13	LX	passive	DCDC switching node. Connect to external boost inductor (typ. 1 µH). Pins 13, 14, 15 are tied together internally.
14	LX	passive	DCDC switching node. Connect to external boost inductor (typ. 1 µH). Tied to pins 13, 15.
15	LX	passive	DCDC switching node. Connect to external boost inductor (typ. 1 µH). Tied to pins 13, 14.
16	VOUT	power_out	5V boost regulated output (2.4A max). Delivers USB-out supply. Pins 16, 17 tied together internally.
17	VOUT	power_out	5V boost regulated output (2.4A max). Tied to pin 16.
18	DM	bidirectional	USB D− line for DCP handshake / attached-device detection. Supports Apple, Samsung and BC1.2 DCP D+/D− voltage patterns for max charging current.
19	DP	bidirectional	USB D+ line for DCP handshake / attached-device detection. Works with DM to advertise BC1.2 / Apple / Samsung DCP profiles.
20	VIN	power_in	DC 5V charge input (from USB Micro-B / Type-A adapter). Operating range 4.75-5.5V; UVLO 4.5V rising, 200 mV hysteresis. Pins 20, 21 tied together internally.
21	VIN	power_in	DC 5V charge input. Tied to pin 20.
22	LIGHT	output	Flashlight LED driver output, open-drain, drives external LED up to 100 mA. Toggled by KEY long-press. Tie to GND if flashlight unused so IC auto-disables the feature.
23	VSET	input	Battery type/voltage select. Float → 4.2V battery; tie to GND → 4.35V battery; tie to VBAT → 4.4V battery.
24	L1/SCK	bidirectional	Battery-level LED driver pin L1; also acts as the I2C SCK clock line when I2C function is enabled.
25	GND	power_in	Exposed thermal pad (EPAD). Power ground and heat-sink; must be soldered to PCB ground for proper thermal and electrical operation.

Key specifications

Parameter	Value
Manufacturer	INJOINIC
Package	QFN-24-EP(4x4)
Category	PMIC
Pins	25

Ordering variants

Same part, different packaging or reel option.

IP5209T

CAD (KiCad official)

Symbol: IP5209T
Footprint: Package_DFN_QFN:QFN-24-1EP_4x4mm_P0.5mm_EP2.7x2.7mm
3D model: QFN-24-EP(4x4) (KiCad packages3D, STEP)

3D model downloads

Two STEP files. Same geometry, different body top:

File	Size	Use it when
`ip5209t.step`	277 KB	You want the bare part, or you mark your own boards.
`ip5209t-etched.step`	1.8 MB	You want the part with `IP5209T` already on it.

The marking in the etched file is real recessed geometry cut into the solid, not a texture or a decal: 441 faces against 158 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: INJOINIC datasheet (14 pp, sha256 5ffc084f061c59e6, 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