# SGM431VBXN3LG

**SGMICRO** · Voltage Reference · SOT-23

SGM431VBXN3LG from SGMICRO, in a SOT-23. Pinout and pin descriptions extracted from the manufacturer datasheet (extract_pins, cross-checked by a second model); symbol, footprint, and 3D from KiCad-official CAD.

## Pinout

| Pin | Name | Type | Function |
|---|---|---|---|
| 1 | REF | input | Threshold input relative to the common anode; the internal reference is approximately 1.24V, and the cathode voltage is set by the external divider tied to this pin. |
| 2 | CATHODE | bidirectional | Shunt current/voltage input; the cathode voltage must stay between VREF and 18V and the cathode current between 0.1mA and 70mA. |
| 3 | ANODE | passive | Common pin, normally connected to ground; all voltage ratings are referenced to the anode. |

## Key specifications

| Parameter | Value |
|---|---|
| Manufacturer | SGMICRO |
| Package | SOT-23 |
| Category | Power Management (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 Voltage (TJ = +25℃) | VREF | 1.234 | 1.24 | 1.246 | V | VKA = VREF, IKA = 10mA, TJ = +25℃ | 4 |
| Reference Voltage (TJ = -40℃ to +125℃) | VREF | 1.225 |  | 1.255 | V | VKA = VREF, IKA = 10mA, TJ = -40℃ to +125℃ | 4 |
| Deviation of Reference Input Voltage over Full Temperature Range | VI(DEV) |  | 2 | 10 | mV | VKA = VREF, IKA = 10mA | 4 |
| Ratio of Change in Reference Voltage to the Change in Cathode Voltage | ΔVREF/ΔVKA |  | -0.1 | -0.2 | mV/V | IKA = 10mA, VKA = VREF to 18V | 4 |
| Reference Input Current | IREF |  | 0.06 | 0.15 | µA | IKA = 10mA, R1 = 10kΩ, R2 = open, see Figure 9 | 4 |
| Deviation of Reference Input Current over Full Temperature Range | II(DEV) |  | 0.15 | 0.5 | µA | IKA = 10mA, R1 = 10kΩ, R2 = open, see Figure 9 | 4 |
| Minimum Cathode Current for Regulation | IMIN |  | 65 | 80 | µA | VKA = VREF | 4 |
| Off-State Cathode Current | IK(OFF) |  | 0.01 | 0.1 | µA | VKA = 18V, VREF = 0V | 4 |
| Dynamic Impedance | /ZKA/ |  | 0.1 | 0.3 | Ω | VKA = VREF, f ≤ 1kHz, IKA = 0.1mA to 70mA | 4 |
| Cathode Voltage (recommended) | VKA |  |  | 18 | V |  | 2 |
| Operating Junction Temperature Range (recommended) | TJ | -40 |  | 125 | ℃ |  | 2 |
| Junction Temperature (absolute maximum) | TJ |  |  | 150 | ℃ |  | 2 |
| Storage Temperature Range | TSTG | -65 |  | 150 | ℃ |  | 2 |
| Lead Temperature (Soldering) |  |  |  | 260 | ℃ | Soldering, 10s | 2 |
| Package Thermal Resistance, SOT-23 (junction to ambient) | θJA |  | 290 |  | ℃/W | SOT-23 | 2 |

## CAD (KiCad official)

- Symbol: `SGM431VBXN3LG`
- Footprint: `Package_TO_SOT_SMD:SOT-23`
- 3D model: SOT-23 (KiCad packages3D, STEP)
- 3D model files: `sgm431vbxn3lg-etched.step` / `sgm431vbxn3lg-etched.glb` carry the MPN laser-etched on the die in a toggleable `Adom.LaserEtch` group (Fusion-ready); `sgm431vbxn3lg.step` / `sgm431vbxn3lg.glb` are the bare package body.

## Provenance

Data extracted from the manufacturer datasheet, not a distributor listing:

- **Datasheet:** [SGMICRO datasheet](https://jlcpcb.com/api/file/downloadByFileSystemAccessId/8552187965658329088) (16 pp, sha256 `5277ea25e407e75a`, retrieved 2026-10-17, tier: lcsc)
- **Extractor:** parts-factory `2.0.0` / `extract_pins 0.3`, primary `claude-haiku-5-5` (text), consensus `claude-sonnet-5-5` (agreed), guards: pin_guards 0.1: passed. Pins are checked against the footprint pad set and their cited datasheet pages before publish.
- **CAD:** KiCad official libraries (CC-BY-SA 4.0).

[Datasheet PDF](docs/sgm431vbxn3lg-datasheet.pdf)