# TL1431QDR

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

TL1431QDR 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 | bidirectional | Shunt current/voltage input; the datasheet limits cathode current to 1 mA to 100 mA under recommended operating conditions and -100 mA to 150 mA as an absolute maximum. |
| 2 | ANODE | power_in | Common pin normally connected to ground, and all voltage values are referenced to ANODE. |
| 3 | ANODE | power_in | Common pin normally connected to ground, and all voltage values are referenced to ANODE; ANODE terminals are connected internally. |
| 4 | NC | unconnected | No internal connection. |
| 5 | NC | unconnected | No internal connection. |
| 6 | ANODE | power_in | Common pin normally connected to ground, and all voltage values are referenced to ANODE; ANODE terminals are connected internally. |
| 7 | ANODE | power_in | Common pin normally connected to ground, and all voltage values are referenced to ANODE; ANODE terminals are connected internally. |
| 8 | REF | input | Threshold input relative to common ground; the reference input current is limited to -0.05 mA to 10 mA as an absolute maximum. |

## Key specifications

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

## 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 | VI(ref) | 2490 | 2500 | 2510 | mV | VKA = VI(ref), TA = 25°C | 6 |
| Reference input voltage over temperature | VI(ref) | 2470 |  | 2530 | mV | VKA = VI(ref), TA = -40°C to 125°C | 6 |
| Deviation of reference input voltage over full temperature range | VI(dev) |  | 17 | 55 | mV | VKA = VI(ref), TA = -40°C to 125°C | 6 |
| Ratio of change in reference input voltage to change in cathode voltage | ΔVKA/ΔVI(ref) |  | -1.1 | -2 | mV/V | ΔVKA = 3V to 36V, TA = -40°C to 125°C | 6 |
| Reference input current | II(ref) |  | 1.5 | 2.5 | µA | R1 = 10kΩ, R2 = ∞, TA = 25°C | 6 |
| Reference input current over temperature | II(ref) |  |  | 4 | µA | R1 = 10kΩ, R2 = ∞, TA = -40°C to 125°C | 6 |
| Deviation of reference input current over full temperature range | II(dev) |  | 0.5 | 2 | µA | R1 = 10kΩ, R2 = ∞, TA = -40°C to 125°C | 6 |
| Minimum cathode current for regulation | Imin |  | 0.45 | 1 | mA | VKA = VI(ref), TA = 25°C | 6 |
| Off-state cathode current | Ioff |  | 0.18 | 0.5 | µA | VKA = 36V, VI(ref) = 0, TA = 25°C | 6 |
| Off-state cathode current over temperature | Ioff |  |  | 2 | µA | VKA = 36V, VI(ref) = 0, TA = -40°C to 125°C | 6 |
| Output impedance | /zKA/ |  | 0.2 | 0.4 | Ω | VKA = VI(ref), f ≤ 1kHz, IKA = 1mA to 100mA, TA = 25°C | 6 |
| Cathode voltage | VKA |  |  | 36 | V | Minimum is VI(ref) | 4 |
| Cathode current | IKA | 1 |  | 100 | mA |  | 4 |
| Operating free-air temperature, TL1431Q | TA | -40 |  | 125 | °C | TL1431Q | 4 |
| Cathode voltage | VKA |  |  | 37 | V | with respect to ANODE | 4 |
| Continuous cathode current | IKA | -100 |  | 150 | mA |  | 4 |
| Reference input current | II(ref) | -0.05 |  | 10 | mA |  | 4 |
| Lead temperature |  |  |  | 260 | °C | 1.6mm (1/16in) from case for 10s | 4 |
| Junction temperature | TJ |  |  | 150 | °C |  | 4 |
| Storage temperature | Tstg | -65 |  | 150 | °C |  | 4 |
| Electrostatic discharge, human-body model | V(ESD) | -2000 |  | 2000 | V | HBM, per ANSI/ESDA/JEDEC JS-001 | 4 |
| Electrostatic discharge, charged-device model | V(ESD) | -1000 |  | 1000 | V | CDM, per JEDEC JESD22-C101 | 4 |
| Junction-to-ambient thermal resistance (D, SOIC) | RθJA |  | 114.7 |  | °C/W |  | 4 |
| Junction-to-case (top) thermal resistance (D, SOIC) | RθJC(top) |  | 59 |  | °C/W |  | 4 |
| Junction-to-board thermal resistance (D, SOIC) | RθJB |  | 55.4 |  | °C/W |  | 4 |
| Junction-to-top characterization parameter (D, SOIC) | ψJT |  | 12 |  | °C/W |  | 4 |
| Junction-to-board characterization parameter (D, SOIC) | ψJB |  | 54.8 |  | °C/W |  | 4 |

## CAD (KiCad official)

- Symbol: `TL1431QDR`
- Footprint: `Package_SO:SOIC-8_3.9x4.9mm_P1.27mm`
- 3D model: SOIC-8 (KiCad packages3D, STEP)
- 3D model files: `tl1431qdr-etched.step` / `tl1431qdr-etched.glb` carry the MPN laser-etched on the die in a toggleable `Adom.LaserEtch` group (Fusion-ready); `tl1431qdr.step` / `tl1431qdr.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/lit/ds/symlink/tl1431.pdf) (41 pp, sha256 `482f5ddecabc080b`, retrieved 2026-11-05, tier: manufacturer)
- **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/tl1431qdr-datasheet.pdf)