TP4059 from TOPPOWER Nanjing Extension Microelectronics, in a SOT-23-6. 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 the internal switch while charging is in progress; high-impedance otherwise. When no battery is connected, this pin outputs a pulse signal (flicker cycle ~0.5-2s with a 10uF BAT capacitor) indicating no battery installed. Drive capability ICHRG=5mA gives VOL <= 0.6V (typ 0.3V).
2	GND	power_in	Device ground reference for all internal circuitry.
3	BAT	power_out	Charging current output to the single Li-ion cell. Regulates the final float voltage to 4.2V (4.158-4.242V) via an internal precision divider. Delivers up to 600mA (RPROG=1.5k typ) in constant-current mode, and drops to 1/10 of the set value to terminate charging. Absolute max range -4.2V to 7V. Recommended 10uF ceramic bypass capacitor close to the pin.
4	VCC	power_in	Positive input supply (USB or adapter). Operating range 4.0V to 9.0V (absolute max -0.3V to 9V). Must be bypassed by at least 1uF close to the pin. When VCC falls to within 30mV of VBAT, the part enters shutdown and IBAT drops below 2uA. UVLO threshold typ 3.6V (3.4-3.8V, low-to-high).
5	STDBY	output	Open-drain end-of-charge status output. Pulled low by the internal switch once the battery is fully charged; high-impedance otherwise (including during charge and during a recharge cycle). Typically drives an LED (green) to VCC through a series resistor.
6	PROG	input	Charge-current program, monitor and shutdown pin. Connect a 1% resistor RPROG from PROG to GND to set the constant-current value (IBAT ~= 1000/RPROG for IBAT <= 0.3A; e.g. RPROG=1.5k -> ~600mA, 10k -> ~100mA). In constant-current mode the pin is regulated to 1.0V (0.9-1.1V). Disconnecting RPROG lets an internal 2.5uA current pull PROG above the 2.7V shutdown threshold, placing the charger in shutdown (ICC drops to ~145uA). Absolute max -0.3V to VCC+0.3V; max source current 800uA.

Key specifications

Parameter	Value
Manufacturer	TOPPOWER Nanjing Extension Microelectronics
Package	SOT-23-6
Category	PMIC
Pins	6

Ordering variants

Same part, different packaging or reel option.

TP4059-42-SOT236

CAD (KiCad official)

Symbol: TP4059
Footprint: Package_TO_SOT_SMD:SOT-23-6
3D model: SOT-23-6 (KiCad packages3D, STEP)

3D model downloads

Two STEP files. Same geometry, different body top:

File	Size	Use it when
`tp4059.step`	97 KB	You want the bare part, or you mark your own boards.
`tp4059-etched.step`	1.4 MB	You want the part with `TP4059` already on it.

The marking in the etched file is real recessed geometry cut into the solid, not a texture or a decal: 346 faces against 117 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 (11 pp, sha256 0407fe89e2a9092b, 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