TP4055 from TOPPOWER Nanjing Extension Microelectronics, in a SOT-23-5. 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	CHRG	output	Open-drain charge status output. Pulled low by an internal switch while charging is in progress; high-impedance otherwise. Outputs a ~0.5-2 s pulse (with 10 uF at BAT) when no battery is connected.
2	GND	power_in	Ground terminal / device reference.
3	BAT	power_out	Battery connection pin. Supplies charge current to the Li-ion cell and regulates the final float voltage to 4.2 V via an internal precision divider (disconnected in shutdown). Bypass with 10 uF; absolute current 500 mA.
4	VCC	power_in	Positive input supply, 4 V to 9 V (abs max -0.3 V to 9 V). Bypass with at least 10 uF. When VCC drops within 30 mV of VBAT the part enters low-power sleep (IBAT < 1 uA).
5	PROG	bidirectional	Charge-current program, monitor, and shutdown pin. A 1% resistor RPROG to GND sets IBAT (e.g. 1.66 kOhm -> 500 mA); pin sits at 1 V in constant-current mode. Leaving RPROG open lets an internal 2.5 uA source pull the pin above the 2.7 V shutdown threshold, stopping charge and reducing supply current to ~40 uA.

Key specifications

Parameter	Value
Manufacturer	TOPPOWER Nanjing Extension Microelectronics
Package	SOT-23-5
Category	PMIC
Pins	5

Ordering variants

Same part, different packaging or reel option.

TP4055-42-SOT235

CAD (KiCad official)

Symbol: TP4055
Footprint: Package_TO_SOT_SMD:SOT-23-5
3D model: SOT-23-5 (KiCad packages3D, STEP)

Provenance

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

Datasheet: TOPPOWER Nanjing Extension Microelectronics datasheet (9 pp, sha256 051a3c3b2441467b, retrieved 2026-08-17, tier: manufacturer)
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