component
LM431CIM3X
Public Unreviewedby Ray
Texas Instruments Voltage Reference, SOT-23. Datasheet-verified pinout, KiCad symbol/footprint/3D.
3D Model
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Symbol & Footprint
Schematic Symbol
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PCB Footprint
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Datasheet
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README
markdownLM431CIM3X
Texas Instruments · Voltage Reference · SOT-23
LM431CIM3X from Texas Instruments, 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 | CATHODE | passive | Shunt cathode / output. Sinks current when V(REF) exceeds the internal 2.5 V reference. Absolute maximum cathode voltage 37 V; continuous cathode current rated -10 mA to 150 mA; recommended cathode current 1 mA to 100 mA for regulation. Dynamic output impedance is typically 0.5 Ω (LM431C). |
| 2 | REFERENCE | input | Reference (control) input to the internal error amplifier, compared against the 2.495 V internal V_REF. Typically driven from a two-resistor divider between CATHODE and ANODE to program the shunt voltage V_Z = V_REF*(1 + R1/R2). Reference input current I_REF ≈ 2 µA typical (4 µA max); absolute max ranges from −0.5 V to 10 mA. |
| 3 | ANODE | passive | Anode / common return, normally tied to circuit ground. Return path for both cathode shunt current and the reference-divider current. |
Key specifications
| Parameter | Value |
|---|---|
| Manufacturer | Texas Instruments |
| Package | SOT-23 |
| Category | PMIC |
| Pins | 3 |
Ordering variants
Same part, different packaging or reel option.
LM431CIM3XLM431CIM3XAIM3LM431CIM3XAIM3XLM431CIM3XBIM3LM431CIM3XBIM3XLM431CIM3XAIMLM431CIM3XBIMLM431CIM3XILPLM431CIM3XCLPLM431CIM3XALPLM431CIM3XBLPLM431CIM3XILPE3LM431CIM3XILPM
CAD (KiCad official)
- Symbol:
LM431CIM3X - Footprint:
Package_TO_SOT_SMD:SOT-23 - 3D model: SOT-23 (KiCad packages3D, STEP)
Provenance
Data extracted from the manufacturer datasheet, not a distributor listing:
- Datasheet: Texas Instruments datasheet (37 pp, sha256
4648ba9da77339e3, 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).