# TL431QDR

**Texas Instruments** · Voltage Reference · SOIC-8

TL431QDR from Texas Instruments, in a SOIC-8. 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 | CATHODE | output | Cathode (shunt output) terminal; provides regulated voltage from Vref (2.495V typ.) to 36V with sink current capability of 1-100 mA continuous |
| 2 | ANODE | power_in | Anode (common return/ground) reference terminal; must be connected to circuit ground |
| 3 | ANODE | power_in | Anode (common return/ground) reference terminal; must be connected to circuit ground |
| 4 | NC | unconnected | No internal connection; can be left open or connected to ground |
| 5 | NC | unconnected | No internal connection; can be left open or connected to ground |
| 6 | ANODE | power_in | Anode (common return/ground) reference terminal; must be connected to circuit ground |
| 7 | ANODE | power_in | Anode (common return/ground) reference terminal; must be connected to circuit ground |
| 8 | REF | input | Reference input terminal; sets threshold voltage to Vref = 2.495V ±0.5% (typ. at 25°C) with required input bias current Iref = 2-4 µA |

## Key specifications

| Parameter | Value |
|---|---|
| Manufacturer | Texas Instruments |
| Package | SOIC-8 |
| Category | Power Management (PMIC) |
| Pins | 8 |

## CAD (KiCad official)

- Symbol: `TL431QDR`
- Footprint: `Package_SO:SOIC-8_3.9x4.9mm_P1.27mm`
- 3D model: SOIC-8 (KiCad packages3D, STEP)
- 3D model files: `tl431qdr-etched.step` / `tl431qdr-etched.glb` carry the MPN laser-etched on the die in a toggleable `Adom.LaserEtch` group (Fusion-ready); `tl431qdr.step` / `tl431qdr.glb` are the bare package body.

## Provenance

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

- **Datasheet:** [Texas Instruments datasheet](https://www.ti.com/cn/lit/gpn/tl431) (86 pp, sha256 `313277b9351e61ed`, retrieved 2026-10-07, tier: lcsc)
- **Datasheet language:** Chinese. Pin names, descriptions, and specs on this page were extracted and translated to English by ds2sf; the linked PDF is the manufacturer original.
- **Extractor:** parts-factory `2.0.0` / `extract_pins 0.3`, primary `claude-haiku-4-5-20251001` (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/tl431qdr-datasheet.pdf)