# AZ431AN-ATRG1

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

AZ431AN-ATRG1 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 input to the internal error amplifier. The device regulates so that V(REF) equals the internal 2.5 V bandgap reference. Reference input current range is +/-10 mA absolute max; typical bias current is in the microamp range. Connect to the tap of the external resistor divider from CATHODE to ANODE that sets the shunt regulation voltage: V_KA = (1 + R1/R2) * V_REF. |
| 2 | CATHODE | passive | Cathode of the shunt regulator (equivalent to a programmable Zener cathode). Sinks the regulated current (I_KA) from the load through an internal pass transistor when V_KA reaches the programmed threshold. Rated V_KA up to 40 V absolute max (36 V recommended), continuous cathode current -100 to +150 mA absolute max (1-100 mA recommended operating). |
| 3 | ANODE | passive | Anode of the shunt regulator; the internal reference and error amplifier ground return. Connect to the negative side of the shunt (typically circuit ground / the low side of the R1/R2 divider). |

## Key specifications

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

## Ordering variants

- `AZ431AN-ATRG1`
- `AZ431AN-ATRG1AZ431ANTR-G1`

## 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 |  |  | -1 | -2.7 | mV/V | IKA = 10mA, VKA = 10V to VREF | 5 |
| Ratio of Change in Reference Voltage to Change in Cathode Voltage |  |  | -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 |  | 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) |  |  |  | 2000 | V | Human Body Model | 4 |
| Cathode Voltage (recommended) | VKA |  |  | 36 | V | Minimum printed as VREF (symbol, not a number); left null | 4 |
| Cathode Current (recommended) | IKA | 1 |  | 100 | mA |  | 4 |
| Operating Ambient Temperature Range | TA | -40 |  | 125 | °C |  | 4 |
| Thermal Resistance (Junction to Ambient), SOT23 | θJA |  | 380 |  | °C/W | Junction to ambient, SOT23, as printed in Absolute Maximum Ratings | 4 |
| Thermal Resistance (Junction to Case), SOT23 | θJC |  | 135.48 |  | °C/W |  | 5 |

## CAD (KiCad official)

- Symbol: `AZ431AN-ATRG1`
- Footprint: `Package_TO_SOT_SMD:SOT-23`
- 3D model: SOT-23 (KiCad packages3D, STEP)
- 3D model files: `az431an-atrg1-etched.step` / `az431an-atrg1-etched.glb` carry the MPN laser-etched on the die in a toggleable `Adom.LaserEtch` group (Fusion-ready); `az431an-atrg1.step` / `az431an-atrg1.glb` are the bare package body.

## 3D model downloads

Two STEP files. Same geometry, different body top:

| File | Size | Use it when |
|---|---|---|
| [`az431an-atrg1.step`](az431an-atrg1.step) | 59 KB | You want the bare part, or you mark your own boards. |
| [`az431an-atrg1-etched.step`](az431an-atrg1-etched.step) | 1.7 MB | You want the part with `AZ431AN-ATRG1` already on it. |

The marking in the etched file is real recessed geometry cut into the solid, not a
texture or a decal: 445 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-ATRG1.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-atrg1-datasheet.pdf)