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Contents

README

markdown

SP4521

TPOWER · Battery Management · ESOP-8

SP4521 from TPOWER, 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 VDD power_in Charger power input. Recommended operating range 4.6V to 5.5V (typ. 5V). Bypass locally with ceramic capacitor to GND.
2 LED1 output Battery fuel-gauge / status LED1 driver. Sinks approximately 2mA (at VBAT=4V). Flashes at 1Hz during charge and at 2Hz to indicate low battery (VBAT<3.05V).
3 LED2 output Battery fuel-gauge / status LED2 driver. Sinks approximately 2mA (at VBAT=4V). Illuminates according to charge/discharge state-of-charge table.
4 LED3 output Battery fuel-gauge / status LED3 driver. Sinks approximately 2mA (at VBAT=4V). Illuminates according to charge/discharge state-of-charge table.
5 SWT input Push-button input. Short press powers on the device and displays battery level; double-click powers off. Typically pulled to GND through a momentary switch with a series resistor.
6 BAT bidirectional Lithium-ion battery positive terminal. Charge output during charging (up to 1A, regulated to 4.2V or 4.35V option); source input for boost during discharge. Discharge terminates at 2.9V (typ).
7 SW passive Switching node of the synchronous boost/buck power stage. Connects to external 2.2µH inductor (saturation current > 3A). Switching frequency 400-600kHz (typ 500kHz).
8 OUT power_out Boost converter output, regulated to 5V (4.8-5.2V) at up to 1A load. Requires low-ESR bypass capacitance (e.g., 2×10µF ceramic).
9 GND power_in Exposed thermal pad and system ground return. Must be soldered to a large PCB ground plane for proper thermal dissipation and electrical reference.

Key specifications

Parameter Value
Manufacturer TPOWER
Package ESOP-8
Category PMIC
Pins 9

CAD (KiCad official)

  • Symbol: SP4521
  • Footprint: Package_SO:SOIC-8-1EP_3.9x4.9mm_P1.27mm_EP2.29x3mm
  • 3D model: ESOP-8 (KiCad packages3D, STEP)

3D model downloads

Two STEP files. Same geometry, different body top:

File Size Use it when
sp4521.step 125 KB You want the bare part, or you mark your own boards.
sp4521-etched.step 1.5 MB You want the part with SP4521 already on it.

The marking in the etched file is real recessed geometry cut into the solid, not a texture or a decal: 380 faces against 152 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: TPOWER datasheet (6 pp, sha256 1477344ba02e2d55, 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