# TL431C

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

TL431C from HTC Korea TAEJIN Tech, in a TO-92. 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; the TL431C reference is 2.495V typ. (2.483V to 2.507V min to max at IK=10mA, VKA=VREF). |
| 2 | Anode | power_in | Anode is the ground connection of the device, per the pin description table. |
| 3 | Cathode | input | Cathode is the input supply voltage pin, with cathode voltage up to 40V (absolute maximum VKA is 42V) and cathode current 100 to 150 mA continuous. |

## Key specifications

| Parameter | Value |
|---|---|
| Manufacturer | HTC Korea TAEJIN Tech |
| Package | TO-92 |
| 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 (TL431C, 0.5%) | VREF | 2.483 | 2.495 | 2.507 | V | VKA = VREF, IK = 10mA | 4 |
| Cathode Voltage (absolute maximum) | VKA |  |  | 42 | V |  | 1 |
| Cathode Current Range (continuous) | IK | -100 |  | 150 | mA |  | 1 |
| Reference Input Current Range | IREF | -0.05 |  | 10 | mA |  | 1 |
| Junction Temperature Range | TJ | -40 |  | 150 | ℃ |  | 1 |
| Operating Temperature Range | TOPR | -40 |  | 125 | ℃ |  | 1 |
| Storage Temperature Range | TSTG | -65 |  | 150 | ℃ |  | 1 |
| Cathode Voltage (recommended) | VKA |  |  | 40 | V | minimum is VREF | 2 |
| Cathode Current (recommended) | IK | 0.5 |  | 100 | mA |  | 2 |
| 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 | IK = 10mA, ΔVKA = 10V | 4 |
| Ratio of Change in Reference Input Voltage to Change in Cathode Voltage | 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 | 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 |
| Equivalent Full Range Temperature Coefficient | αVREF |  |  | 50 | PPM/℃ | Equivalent full range (feature list) | 1 |

## CAD (KiCad official)

- Symbol: `TL431C`
- Footprint: `Package_TO_SOT_THT:TO-92_Inline`
- 3D model: TO-92 (KiCad packages3D, STEP)
- 3D model files: `tl431c-etched.step` / `tl431c-etched.glb` carry the MPN laser-etched on the die in a toggleable `Adom.LaserEtch` group (Fusion-ready); `tl431c.step` / `tl431c.glb` are the bare package body.

## Provenance

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

- **Datasheet:** [HTC Korea TAEJIN Tech datasheet](docs/tl431c-datasheet.pdf) (12 pp, sha256 `66b4ce853f1e463b`, retrieved 2026-11-04, 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/tl431c-datasheet.pdf)