IP5506_BZ_188 from INJOINIC, in a SOP-16. 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	VOUT	power_out	DC-DC 5V boost output. Typ 5.12V @ 0A, 5.0V @ 2.4A load; supports up to 2.1A continuous. Bypass close to pin with bulk + ceramic caps.
2	VIN	power_in	DC-DC 5V charging input from external adapter/USB-B. Recommended 4.5-5.8V; OVP 5.8V typ, UVP 4.5V typ; absolute max 12V.
3	KEY	input	User pushbutton input and flashlight (WLED) drive pin. Short-press to power on, long-press ~2s to toggle flashlight; behavior selected by FSEL resistor.
4	LED5	output	Digital-tube / battery-gauge LED drive pin 5. Drives one segment of the 188-type 7-segment display (or one of the 5 battery-level LEDs). ~5 mA typ (4-8 mA).
5	LED4	output	Digital-tube / battery-gauge LED drive pin 4. ~5 mA typ IO drive current.
6	LED3	output	Digital-tube / battery-gauge LED drive pin 3. ~5 mA typ IO drive current.
7	LED2	output	Digital-tube / battery-gauge LED drive pin 2. ~5 mA typ IO drive current.
8	FCap	input	Battery-cell initial capacity setting pin (used by the internal fuel gauge to seed the Coulomb-counter model).
9	FSEL	input	Key/flashlight behavior select. Resistor-to-GND chooses one of five modes: 1K, 33K, 51K, 82K, 100K (each selects a different short/long-press and flashlight scheme; 100K enables vibration-switch mode).
10	LED1	output	Digital-tube / battery-gauge LED drive pin 1. ~5 mA typ IO drive current.
11	VSET	input	Battery-type (CV target) select. Resistor divider from VCC sets CV target: GND=4.20V, 1V=4.30V, VCC=4.35V, 2V=4.40V. Example dividers: NC/0R, 300K/150K, 0R/NC, 150K/300K per Fig. 8.
12	GND	power_in	System (signal) ground.
13	VCC	power_out	Internal 3.1V LDO output (3.05-3.15V) used to bias internal blocks and as reference for VSET divider. Decouple with a ceramic cap to GND; do not load externally beyond bias needs.
14	VBAT	power_in	System supply and battery-voltage sense. Operating range 3.0-4.4V (low-battery cutoff 2.9-3.0V). Connects to the Li-ion cell positive terminal.
15	CSIN	input	Cell voltage Kelvin-sense input to the 14-bit ADC / fuel gauge. Route separately from the VBAT power trace to the battery + terminal for accurate voltage measurement.
16	LX	output	DC-DC switching node; connect to the external 1 uH inductor. Internal synchronous PMOS/NMOS (rDS(on) ~40/35 mOhm) switch at 500 kHz nominal (450-550 kHz) for both charge and boost modes.
17	GND	power_in	Exposed thermal pad / power ground. Must be soldered to the PCB ground plane for both heat dissipation and low-impedance return; connect to signal GND (pin 12) at the pad.

Key specifications

Parameter	Value
Manufacturer	INJOINIC
Package	SOP-16
Category	PMIC
Pins	17

Ordering variants

Same part, different packaging or reel option.

IP5506_BZ_188
IP5506_BZ_LED

CAD (KiCad official)

Symbol: IP5506_BZ_188
Footprint: Package_SO:SOIC-16_3.9x9.9mm_P1.27mm
3D model: SOP-16 (KiCad packages3D, STEP)

Provenance

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

Datasheet: INJOINIC datasheet (18 pp, sha256 8b74e81650e27e7d, 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