# TL431CTA

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

TL431CTA 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 | input | Reference voltage input, which for TL431C is 2.483 V to 2.507 V at VKA = VREF and IK = 10 mA, with a reference input current of 1.8 uA typ. and 4.0 uA max. |
| 2 | Anode | passive | Common terminal of the shunt regulator that the cathode current returns to; the pin description table labels this pin Ground. |
| 3 | Cathode | passive | Cathode is the regulated shunt output, recommended to operate from VREF up to 40 V with a cathode current of 0.5 mA to 100 mA, and absolute maximum cathode voltage of 42 V. |

## Key specifications

| Parameter | Value |
|---|---|
| Manufacturer | HTC Korea TAEJIN Tech |
| Package | TO-92-2.54mm |
| Category | Power Management ICs |
| 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 | VREF | 2.483 | 2.495 | 2.507 | V | VKA=VREF, IK=10mA (TL431C column) | 4 |
| Deviation of Reference Input Voltage | 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 | ΔVREF/ΔVKA |  | -1.4 | -2.7 | mV/V | ΔVKA=10V-VREF, IK=10mA | 4 |
| Ratio of Change in Reference Input Voltage to Change in Cathode Voltage | ΔVREF/ΔVKA |  | -1 | -2 | mV/V | ΔVKA=36V-10V, IK=10mA | 4 |
| Reference Input Current | IREF |  | 1.8 | 4 | uA | IKA=10mA, R1=10kΩ, R2=∞ | 4 |
| Deviation of Reference Input Current | 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 | VKA |  |  | 42 | V |  | 1 |
| Cathode Current Range (Continuous) | IK | -100 |  | 150 | mA | Continuous | 1 |
| Reference Input Current Range | IREF | -0.05 |  | 10 | mA |  | 1 |
| Junction Temperature Range | TJ | -40 |  | 150 | ℃ |  | 1 |
| Operating Temperature Range | TOPR | -40 |  | 125 | ℃ | Operating temperature range applies unless otherwise specified | 1 |
| Storage Temperature Range | TSTG | -65 |  | 150 | ℃ |  | 1 |
| Cathode Voltage | VKA |  |  | 40 | V | Minimum printed as VREF (symbolic, not numeric) | 2 |
| Cathode Current | IK | 0.5 |  | 100 | mA |  | 2 |

## CAD (KiCad official)

- Symbol: `TL431CTA`
- Footprint: `Package_TO_SOT_THT:TO-92_Inline`
- 3D model: TO-92-2.54mm (KiCad packages3D, STEP)
- 3D model files: `tl431cta-etched.step` / `tl431cta-etched.glb` carry the MPN laser-etched on the die in a toggleable `Adom.LaserEtch` group (Fusion-ready); `tl431cta.step` / `tl431cta.glb` are the bare package body.

## Provenance

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

- **Datasheet:** [HTC Korea TAEJIN Tech datasheet](docs/tl431cta-datasheet.pdf) (12 pp, sha256 `0a0d5fc0a3221190`, retrieved 2026-10-29, 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/tl431cta-datasheet.pdf)