# TL431ATA

**HTC Korea TAEJIN Tech** · Voltage Reference · TO-92-2.54mm

TL431ATA from HTC Korea TAEJIN Tech, in a TO-92-2.54mm. 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 | Reference | passive | Reference voltage input (VREF, approx. 2.5 V, 2.495 V typical for the TL431A) that the internal error amplifier regulates against. |
| 2 | Anode | power_in | Listed as Ground in the pin description table; it is the common return of the shunt regulator. |
| 3 | Cathode | input | Cathode is the regulated output and is listed as Input Supply Voltage; recommended VKA is VREF to 40 V with cathode current IK of 0.5 to 100 mA (absolute maximum VKA 42 V). |

## Key specifications

| Parameter | Value |
|---|---|
| Manufacturer | HTC Korea TAEJIN Tech |
| Package | TO-92-2.54mm |
| 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 Input Voltage (TL431A, 1%) | VREF | 2.47 | 2.495 | 2.52 | V | VKA = VREF, IK = 10mA | 4 |
| Deviation of Reference Input Voltage (TA = Full Range) | ΔVREF/ΔT |  | 8 | 20 | mV | VKA = VREF, IK = 10mA, TA = Full Range | 4 |
| Ratio of Change in Reference Input Voltage to Change in Cathode Voltage (ΔVKA = 10V - VREF) | ΔVREF/ΔVKA |  | -1.4 | -2.7 | mV/V | IK = 10mA, ΔVKA = 10V - VREF | 4 |
| Ratio of Change in Reference Input Voltage to Change in Cathode Voltage (ΔVKA = 36V - 10V) | ΔVREF/ΔVKA |  | -1 | -2 | mV/V | IK = 10mA, ΔVKA = 36V - 10V | 4 |
| Reference Input Current | IREF |  | 1.8 | 4 | uA | IKA = 10mA, R1 = 10kΩ, R2 = ∞ | 4 |
| Deviation of Reference Input Current (TA = Full Range) | ΔIREF/ΔT |  | 0.4 | 1.2 | uA | IK = 10mA, R1 = 10kΩ, R2 = ∞, TA = Full Range | 4 |
| Minimum Cathode Current for Regulation | IK(MIN) |  | 0.5 |  | mA | VKA = VREF | 4 |
| Off-State Cathode Current | IK(OFF) |  | 0.17 | 0.9 | uA | VKA = 36V, VREF = 0 | 4 |
| Dynamic Impedance | ZKA |  | 0.27 | 0.5 | Ω | VKA = VREF, IK = 1mA~100mA, f ≤ 1kHz | 4 |
| Cathode Voltage (recommended) | VKA |  |  | 40 | V | Printed minimum is 'VREF' (symbolic, no numeric value) | 2 |
| Cathode Current (recommended) | IK | 0.5 |  | 100 | mA |  | 2 |
| Cathode Voltage (absolute maximum) | VKA |  |  | 42 | V | Operating temperature range applies unless otherwise specified | 1 |
| Cathode Current Range (Continuous) | IK | -100 |  | 150 | mA | Operating temperature range applies unless otherwise specified | 1 |
| Reference Input Current Range | IREF | -0.05 |  | 10 | mA | Operating temperature range applies unless otherwise specified | 1 |
| Junction Temperature Range | TJ | -40 |  | 150 | ℃ | Operating temperature range applies unless otherwise specified | 1 |
| Operating Temperature Range | TOPR | -40 |  | 125 | ℃ | Operating temperature range applies unless otherwise specified | 1 |
| Storage Temperature Range | TSTG | -65 |  | 150 | ℃ |  | 1 |
| Equivalent Full Range Temperature Coefficient |  |  | 50 |  | ppm/℃ | Stated in Features; no test conditions printed | 1 |

## CAD (KiCad official)

- Symbol: `TL431ATA`
- Footprint: `Package_TO_SOT_THT:TO-92_Inline`
- 3D model: TO-92-2.54mm (KiCad packages3D, STEP)
- 3D model files: `tl431ata-etched.step` / `tl431ata-etched.glb` carry the MPN laser-etched on the die in a toggleable `Adom.LaserEtch` group (Fusion-ready); `tl431ata.step` / `tl431ata.glb` are the bare package body.

## Provenance

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

- **Datasheet:** [HTC Korea TAEJIN Tech datasheet](https://jlcpcb.com/api/file/downloadByFileSystemAccessId/8588895114546040832) (12 pp, sha256 `66b4ce853f1e463b`, retrieved 2026-10-18, 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/tl431ata-datasheet.pdf)