component

FS431M

Public Made by Adom

by adom

FOSAN Voltage Reference, SOT-23. 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 fs431m: 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
fs431m-etched.fit.json fs431m: re-etch, flat white mark read from pin 1 (service-occt 1.4.0) + chip hero · Ray
fs431m-etched.glb fs431m: re-etch, flat white mark read from pin 1 (service-occt 1.4.0) + chip hero · Ray
fs431m-etched.step fs431m: re-etch, flat white mark read from pin 1 (service-occt 1.4.0) + chip hero · Ray
fs431m.glb Publish 0.1.0 · Ray
fs431m.kicad_mod Publish 0.1.0 · Ray
fs431m.kicad_sym Publish 0.1.0 · Ray
fs431m.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
fs431m.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 fs431m: specified limits as data (metadata.characteristics, 18 rows from the datasheet) · Ray
README.md fs431m: specified limits as data (metadata.characteristics, 18 rows from the datasheet) · Ray

FS431M

FOSAN · Voltage Reference · SOT-23

FS431M from FOSAN, in a SOT-23. 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 REF input Reference input. Compared internally against the 2.495 V bandgap reference; typically driven from an external R1/R2 divider between Cathode and Anode to program the regulation voltage. Input current ~1.8 µA typ (4 µA max).
2 K passive Cathode. Shunt regulation terminal; sinks 1-100 mA to hold VKA at the programmed voltage (up to 40 V absolute max, 36 V programmable). Dynamic impedance 0.27 Ω typ.
3 A passive Anode. Common/ground return for the shunt regulator; the resistor divider low side and Vref return are referenced here.

Key specifications

Parameter Value
Manufacturer FOSAN
Package SOT-23
Category PMIC
Pins 3

Electrical characteristics

Limits as printed in the datasheet (page.json metadata.characteristics carries them as data).

Parameter Symbol Min Typ Max Unit Conditions Page
Reference Input Voltage (0.3% grade) VREF 2.488 2.495 2.502 V VKA=VREF IKA=10mA 2
Reference Input Voltage (0.5% grade) VREF 2.483 2.495 2.507 V VKA=VREF IKA=10mA 2
Reference Input Voltage (1% grade) VREF 2.47 2.495 2.52 V VKA=VREF IKA=10mA 2
Deviation of reference input voltage over temperature ΔVREF/ΔT 3 17 mV VKA=VREF IKA=10mA, -20 ~ +70℃ 2
Ratio of change in reference input voltage to change in cathode voltage (ΔVKA=10V~VREF) ΔVREF/ΔVKA -0.4 0 2.7 mV/V IKA=10mA, ΔVKA=10V~VREF 2
Ratio of change in reference input voltage to change in cathode voltage (ΔVKA=36V~10V) ΔVREF/ΔVKA -0.4 0 2 mV/V IKA=10mA, ΔVKA=36V~10V 2
Reference input current IREF 1.8 4 µA IKA=10mA, R1=10kΩ, R2=∞ 2
Deviation of reference input current over full temperature range ΔIREF/ΔT 0.4 1.2 µA IKA=10mA, R1=10kΩ, R2=∞, TA=-20 ~ +85℃ 2
Minimum cathode current for regulation IKA(MIN) 0.25 0.5 mA VKA=VREF 2
Off-state cathode current IKA(OFF) 0.17 1 µA VKA=40V, VREF=0V 2
Dynamic impedance ZKA 0.27 0.5 Ω VKA=VREF, IKA=1 ~ 100mA, f≤1kHz 2
Cathode to anode voltage VKA 40 V 1
Cathode current range IK -100 150 mA 1
Reference input current range IREF -0.05 10 mA 1
Power dissipation PD 200 mW 1
Thermal resistance junction-ambient RΘJA 625 ℃/W 1
Junction and storage temperature TJ,Tstg -40 125 ℃ 1
Operating ambient temperature Top -20 70 ℃ 1

CAD (KiCad official)

  • Symbol: FS431M
  • Footprint: Package_TO_SOT_SMD:SOT-23
  • 3D model: SOT-23 (KiCad packages3D, STEP)
  • 3D model files: fs431m-etched.step / fs431m-etched.glb carry the MPN laser-etched on the die in a toggleable Adom.LaserEtch group (Fusion-ready); fs431m.step / fs431m.glb are the bare package body.

3D model downloads

Two STEP files. Same geometry, different body top:

File Size Use it when
fs431m.step 59 KB You want the bare part, or you mark your own boards.
fs431m-etched.step 1.1 MB You want the part with FS431M already on it.

The marking in the etched file is real recessed geometry cut into the solid, not a texture or a decal: 288 faces against 69 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 (4 pp, sha256 44eae1ca9d167d08, 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