# AZ431AN-ATRE1

**Diodes Incorporated** · Voltage Reference · SOT-23

AZ431AN-ATRE1 from Diodes Incorporated, 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 (feedback) input to the internal error amplifier. Regulation drives VKA so that VREF = 2.500V typical (0.4% initial tolerance for the AZ431A variant) with respect to ANODE. Reference input current 0.7µA typical, 4µA max; absolute maximum reference input current 10mA. |
| 2 | ANODE | power_in | Anode terminal - the low-side of the shunt regulator (analogous to a Zener anode / ground return). All internal circuitry is referenced to this pin. |
| 3 | CATHODE | power_in | Cathode terminal - the regulated (shunted) node. Sinks 1mA to 100mA over the operating range with cathode voltage from VREF to 36V (absolute max VKA = 40V, IKA = -100 to 150mA). Dynamic impedance ZKA = 0.15Ω typical at f ≤ 1kHz. |

## Key specifications

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

## Ordering variants

- `AZ431AN-ATRE1`
- `AZ431AN-ATRE1AR`

## 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 (0.4% grade) | VREF | 2.49 | 2.5 | 2.51 | V | VKA = VREF, IKA = 10mA | 5 |
| Deviation of Reference Voltage Over Full Temperature Range | VREF |  | 4.5 | 8 | mV | VKA = VREF, IKA = 10mA, 0 to +70°C | 5 |
| Deviation of Reference Voltage Over Full Temperature Range | VREF |  | 4.5 | 10 | mV | VKA = VREF, IKA = 10mA, -40 to +85°C | 5 |
| Deviation of Reference Voltage Over Full Temperature Range | VREF |  | 4.5 | 16 | mV | VKA = VREF, IKA = 10mA, -40 to +125°C | 5 |
| Ratio of Change in Reference Voltage to Change in Cathode Voltage | VREF / VKA |  | -1 | -2.7 | mV/V | IKA = 10mA, VKA = 10V to VREF | 5 |
| Ratio of Change in Reference Voltage to Change in Cathode Voltage | VREF / VKA |  | -0.5 | -2 | mV/V | IKA = 10mA, VKA = 36V to 10V | 5 |
| Reference Current | IREF |  | 0.7 | 4 | µA | IKA = 10mA, R1 = 10kΩ, R2 = ∞ | 5 |
| Deviation of Reference Current Over Full Temperature Range | IREF |  | 0.4 | 1.2 | µA | IKA = 10mA, R1 = 10kΩ, R2 = ∞, TA = -40 to +125°C | 5 |
| Minimum Cathode Current for Regulation | IKA (Min) |  | 0.4 | 1 | mA | VKA = VREF | 5 |
| Off-state Cathode Current | IKA (Off) |  | 0.05 | 1 | µA | VKA = 36V, VREF = 0 | 5 |
| Dynamic Impedance | ZKA |  | 0.15 | 0.5 | Ω | VKA = VREF, IKA = 1 to 100mA, f ≤ 1.0kHz | 5 |
| Cathode Voltage | VKA |  |  | 40 | V |  | 4 |
| Cathode Current Range (Continuous) | IKA | -100 |  | 150 | mA | Continuous | 4 |
| Reference Input Current Range | IREF |  |  | 10 | mA |  | 4 |
| Power Dissipation | PD |  |  | 370 | mW | N Package (SOT23) | 4 |
| Junction Temperature | TJ |  |  | 150 | °C |  | 4 |
| Storage Temperature Range | TSTG | -65 |  | 150 | °C |  | 4 |
| ESD (Human Body Model) | ESD |  |  | 2000 | V | Human Body Model | 4 |
| Thermal Resistance (Junction to Ambient) | θJA |  |  | 380 | °C/W | SOT23 | 4 |
| Cathode Voltage | VKA |  |  | 36 | V | Minimum given as VREF | 4 |
| Cathode Current | IKA | 1 |  | 100 | mA |  | 4 |
| Operating Ambient Temperature Range | TA | -40 |  | 125 | °C |  | 4 |
| Thermal Resistance (Junction to Case) | θJC |  | 135.48 |  | °C/W | SOT23 | 5 |

## CAD (KiCad official)

- Symbol: `AZ431AN-ATRE1`
- Footprint: `Package_TO_SOT_SMD:SOT-23`
- 3D model: SOT-23 (KiCad packages3D, STEP)
- 3D model files: `az431an-atre1-etched.step` / `az431an-atre1-etched.glb` carry the MPN laser-etched on the die in a toggleable `Adom.LaserEtch` group (Fusion-ready); `az431an-atre1.step` / `az431an-atre1.glb` are the bare package body.

## 3D model downloads

Two STEP files. Same geometry, different body top:

| File | Size | Use it when |
|---|---|---|
| [`az431an-atre1.step`](az431an-atre1.step) | 59 KB | You want the bare part, or you mark your own boards. |
| [`az431an-atre1-etched.step`](az431an-atre1-etched.step) | 1.6 MB | You want the part with `AZ431AN-ATRE1` already on it. |

The marking in the etched file is real recessed geometry cut into the solid, not a
texture or a decal: 425 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:** [Diodes Incorporated datasheet](https://www.diodes.com/assets/Datasheets/AZ431AN-ATRE1.pdf) (19 pp, sha256 `af7f4848d81a3997`, 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).

[Datasheet PDF](docs/az431an-atre1-datasheet.pdf)