# ME431AXG

**MICRONE** · Voltage Reference · SOT-23

ME431AXG from MICRONE, 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 to the internal error amplifier. Compared against the internal 2.5 V bandgap (VREF); the regulator sinks cathode current to hold REF equal to VREF. Typical reference current 0.7 µA (max 3 µA); absolute max input current 10 mA. |
| 2 | CATHODE | passive | Regulator cathode. Sinks up to 100 mA (max 130 mA) from the rail being regulated; recommended operating VKA from VREF to 36 V (absolute max 40 V). Off-state cathode leakage ≤0.3 µA at VKA=36 V. |
| 3 | ANODE | passive | Regulator anode. Return terminal for cathode current; tied to the low side of the divider / system ground in a shunt-regulator topology. |

## Key specifications

| Parameter | Value |
|---|---|
| Manufacturer | MICRONE |
| Package | SOT-23 |
| Category | PMIC |
| Pins | 3 |

## Ordering variants

Same part, different packaging or reel option.

- `ME431AXG`
- `ME431AXGBXG`
- `ME431AXGAM3G`
- `ME431AXGBM3G`
- `ME431AXGATG`
- `ME431AXGBTG`
- `ME431AXGATBG`
- `ME431AXGBTBG`

## Electrical characteristics

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

| Parameter | Symbol | Min | Typ | Max | Unit | Conditions | Page |
|---|---|---|---|---|---|---|---|
| Cathode voltage (recommended operating) | VKA |  |  | 36 | V |  | 3 |
| Cathode current (recommended operating) | IKA | 1 |  | 100 | mA |  | 3 |
| Operating ambient temperature range | TA | -40 |  | 125 | ℃ |  | 3 |
| Cathode voltage (absolute maximum) | VKA |  |  | 40 | V |  | 2 |
| Cathode current range (absolute maximum) | IKA | -100 |  | 130 | mA | continuous | 2 |
| Reference input current range (absolute maximum) | IREF |  |  | 10 | mA |  | 2 |
| Power dissipation, SOT23 package (absolute maximum) | PD |  |  | 300 | mW | SOT23 package | 2 |
| Power dissipation, SOT23-3 package (absolute maximum) | PD |  |  | 370 | mW | SOT23-3 package | 2 |
| Junction temperature (absolute maximum) | TJ |  |  | 160 | ℃ |  | 2 |
| Storage temperature range (absolute maximum) | TSTG | -65 |  | 150 | ℃ |  | 2 |
| Reference voltage, 0.4% grade | VREF | 2.49 | 2.5 | 2.51 | V | VKA=VREF, IKA=10mA | 3 |
| Reference voltage, 1.0% grade | VREF | 2.475 | 2.5 | 2.525 | V | VKA=VREF, IKA=10mA | 3 |
| Deviation of reference voltage over temperature, 0 to 70℃ | ∆VREF |  | 3 | 10 | mV | VKA=VREF, IKA=10mA | 3 |
| Deviation of reference voltage over temperature, -40 to 150℃ | ∆VREF |  | 3 | 15 | mV | VKA=VREF, IKA=10mA | 3 |
| Dynamic impedance | KA /Z/ |  | 0.15 | 0.5 | Ω | VKA=VREF, IKA=1 to 100mA, f≤1.0KHz | 3 |
| Minimum cathode current for regulation | IKA (MIN) |  | 0.4 | 1 | mA | VKA=VREF | 3 |
| Ratio of change in reference voltage to change in cathode voltage, ΔVKA=10V to VREF | ΔVREF/ΔVKA |  | -0.8 | -2.5 | mV/V | IKA=10mA, ΔVKA=10V to VREF | 3 |
| Ratio of change in reference voltage to change in cathode voltage, ΔVKA=36V to 10V | ΔVREF/ΔVKA |  | -0.6 | -1.5 | mV/V | IKA=10mA, ΔVKA=36V to 10V | 3 |
| Reference current | IREF |  | 0.7 | 3 | μA | IKA=10mA, R1=10KΩ, R2=∝ | 3 |
| Deviation of reference current over full temperature range | ∆IREF |  | 0.1 | 1.2 | μA | IKA=10mA, R1=10KΩ, R2=∝, TA=40 to 150℃ | 3 |
| Off-state cathode current | IKA (OFF) |  | 0.03 | 0.3 | μA | VKA=36V, VREF=0 | 3 |
| Thermal resistance junction-to-ambient, SOT23-3 package | θJA |  |  | 330 | ℃/W | SOT23-3 package | 2 |
| Thermal resistance junction-to-ambient, SOT23 package | θJA |  |  | 350 | ℃/W | SOT23 package | 2 |

## CAD (KiCad official)

- Symbol: `ME431AXG`
- Footprint: `Package_TO_SOT_SMD:SOT-23`
- 3D model: SOT-23 (KiCad packages3D, STEP)
- 3D model files: `me431axg-etched.step` / `me431axg-etched.glb` carry the MPN laser-etched on the die in a toggleable `Adom.LaserEtch` group (Fusion-ready); `me431axg.step` / `me431axg.glb` are the bare package body.

## 3D model downloads

Two STEP files. Same geometry, different body top:

| File | Size | Use it when |
|---|---|---|
| [`me431axg.step`](me431axg.step) | 59 KB | You want the bare part, or you mark your own boards. |
| [`me431axg-etched.step`](me431axg-etched.step) | 1.2 MB | You want the part with `ME431AXG` already on it. |

The marking in the etched file is real recessed geometry cut into the solid, not a
texture or a decal: 324 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:** [MICRONE datasheet](docs/me431axg-datasheet.pdf) (12 pp, sha256 `9c5f9f93004c53ee`, 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](docs/me431axg-datasheet.pdf)