TP5400 from TOPPOWER Nanjing Extension Microelectronics, in a ESOP-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	VOUT	power_out	5V boost output voltage sense/output pin. Requires at least 47uF (tantalum/electrolytic) plus a 0.1uF ceramic and a 5.5V-6.8V TVS clamp for stable operation. Delivers up to 1A typical (1.5A peak, Vbat=3.8V).
2	CHRG	output	Open-drain charge status indicator. Pulls low (VOL <= 0.6V at 5mA) while charging is in progress; high-Z when charge is complete or the chip is in standby/shutdown. Typically drives an LED to VCC through a series resistor.
3	PROG	bidirectional	Charge current program pin. Connect a resistor RPROG from PROG to GND to set IBAT = 1100 / RPROG (e.g. 1.1k -> 1000mA, 1.5k -> 740mA). Regulated to ~1V in constant-current mode; also monitors PROG voltage (<200mV for tTERM ~1.8ms) for C/5 termination. Leaving PROG floating shuts down the charger.
4	STDBY	output	Open-drain standby (charge-complete) indicator. Pulls low (VOL <= 0.6V at 5mA) when the charge cycle has terminated and the chip is in standby; high-Z while charging. Typically drives an indicator LED.
5	VCC	power_in	Charger input supply, 4.0V to 9.0V (typ 5V). Powers the linear charger to BAT. UVLO threshold ~3.6V with 200mV hysteresis; charger inhibited when VCC is within 30mV of VBAT to prevent reverse current. Bypass with 10uF plus a 0.1uF ceramic close to the pin.
6	BAT	bidirectional	Single-cell Li-Ion battery connection. Acts as the charger's regulated output (4.2V ±1% float, up to ~1.2A programmable) and as the boost converter's input (operates for VBAT 3V-4.2V). Recommended bypass 2x22uF. Undervoltage lockout: boost shuts down when VBAT drops below ~3V and re-enables above ~3.3V.
7	GND	power_in	Power / signal ground. Must be well-connected to system ground for stable operation. Exposed die-pad (radiator) on the ESOP-8 package should also be tied to GND (or left floating) for thermal dissipation.
8	LX	power_out	Switching node of the internal boost NMOS power stage. Connect an external inductor (3.3-22uH, typ 10uH) from BAT to LX and a Schottky diode (e.g. SS32) from LX to VOUT. Absolute range -2V to +10V; internal switch RDS(on) ~120mOhm, current limit ~4.5A.

Key specifications

Parameter	Value
Manufacturer	TOPPOWER Nanjing Extension Microelectronics
Package	ESOP-8
Category	PMIC
Pins	8

Ordering variants

Same part, different packaging or reel option.

TP5400ESOP8

CAD (KiCad official)

Symbol: TP5400
Footprint: Package_SO:SOIC-8-1EP_3.9x4.9mm_P1.27mm_EP2.41x3.3mm
3D model: ESOP-8 (KiCad packages3D, STEP)

3D model downloads

Two STEP files. Same geometry, different body top:

File	Size	Use it when
`tp5400.step`	193 KB	You want the bare part, or you mark your own boards.
`tp5400-etched.step`	1.2 MB	You want the part with `TP5400` already on it.

The marking in the etched file is real recessed geometry cut into the solid, not a texture or a decal: 307 faces against 63 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: TOPPOWER Nanjing Extension Microelectronics datasheet (8 pp, sha256 f93dcae2a90a5c70, 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