component

FS4054A

Public Made by Adom

by adom

FOSAN Battery Management, SOT-23-5L. Pinout extracted from the datasheet, KiCad symbol/footprint/3D.

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Generated by kicad-footprint-generator · KiCad file format 20260206
Name Last commit message Last updated
docs fs4054a: re-etch, flat white mark read from pin 1 (service-occt 1.4.0) + chip hero · Ray
viewers pin 1: carry the footprint's marker into the .lbr, the viewer and page.json (silk-marker, drawn, top-left) · Ray
fs4054a-etched.fit.json fs4054a: re-etch, flat white mark read from pin 1 (service-occt 1.4.0) + chip hero · Ray
fs4054a-etched.glb fs4054a: white body in tscircuit (pre-1.8 etch structure under an assembly instance); Ray 2026-10-19: black IC body wit… · Ray
fs4054a-etched.step fs4054a: white body in tscircuit (pre-1.8 etch structure under an assembly instance); Ray 2026-10-19: black IC body wit… · Ray
fs4054a.glb Publish 0.1.0 · Ray
fs4054a.kicad_mod Publish 0.1.0 · Ray
fs4054a.kicad_sym Publish 0.1.0 · Ray
fs4054a.lbr rebuild the library on adom-lbr 2.32.0. The published copy was built by 2.18.0, which imported every KiCad roundrect an… · Ray
fs4054a.step Publish 0.1.0 · Ray
package.json Publish 0.2.0 · Ray
pads.json pin 1: carry the footprint's marker into the .lbr, the viewer and page.json (silk-marker, drawn, top-left) · Ray
page.json fs4054a: white body in tscircuit (pre-1.8 etch structure under an assembly instance); Ray 2026-10-19: black IC body wit… · Ray
README.md fs4054a: laser-etched CAD + chip hero (factory 2.0.0 backfill) · Ray

FS4054A

FOSAN · Battery Management · SOT-23-5L

FS4054A from FOSAN, in a SOT-23-5L. 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 indicator. Pulls low (sinks current, typically driving an LED to VCC through a series resistor such as 330 Ω) while charging is in progress; goes to high impedance when charging terminates (C/10) or the part is in shutdown/standby. Absolute max voltage 7 V.
2 GND power_in Device ground reference for all internal circuitry and the external PROG resistor return.
3 BAT power_out Charge current output to the single-cell Li-ion battery. Regulates to the 4.2 V float voltage in CV mode and delivers up to 500 mA in CC mode. Sources <=2 uA leakage from the battery when VCC is removed. Absolute max 7 V; continuous short-circuit safe. Typically decoupled with ~10 uF to GND.
4 VCC power_in Input supply, 4.5-5.5 V nominal (absolute max 7 V), commonly driven from a USB port or 5 V DC adapter. Undervoltage lockout threshold ~3.4 V; supply current is typically 170 uA during charge and <=25 uA in standby. Decouple with ~1 uF to GND.
5 PROG input Charge current programming pin. Connect a resistor R_PROG from PROG to GND to set the constant-current charge level per I_BAT (mA) = 1000 / R_PROG (kΩ); e.g. 2 kΩ → 500 mA, 10 kΩ → 100 mA. Servos to ~1.03 V in CC mode; can also be used to monitor the actual charge current. Absolute max VCC+0.3 V, 800 uA.

Key specifications

Parameter Value
Manufacturer FOSAN
Package SOT-23-5L
Category PMIC
Pins 5

Ordering variants

Same part, different packaging or reel option.

  • FS4054A
  • FS4054B

CAD (KiCad official)

  • Symbol: FS4054A
  • Footprint: Package_TO_SOT_SMD:SOT-23-5
  • 3D model: SOT-23-5L (KiCad packages3D, STEP)
  • 3D model files: fs4054a-etched.step / fs4054a-etched.glb carry the MPN laser-etched on the die in a toggleable Adom.LaserEtch group (Fusion-ready); fs4054a.step / fs4054a.glb are the bare package body.

3D model downloads

Two STEP files. Same geometry, different body top:

File Size Use it when
fs4054a.step 85 KB You want the bare part, or you mark your own boards.
fs4054a-etched.step 1.4 MB You want the part with FS4054A already on it.

The marking in the etched file is real recessed geometry cut into the solid, not a texture or a decal: 361 faces against 102 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: FOSAN datasheet (5 pp, sha256 42d795be437a7d9c, 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