# TL431ILPR

**Texas Instruments** · Voltage Reference · TO-92-3

TL431ILPR from Texas Instruments, in a TO-92-3. Pinout and pin descriptions extracted from the manufacturer datasheet by ds2sf; symbol, footprint, and 3D from KiCad-official CAD.

## Pinout

| Pin | Name | Type | Function |
|---|---|---|---|
| 1 | CATHODE | bidirectional | Parallel current/voltage input (cathode, K); the terminal whose regulated voltage VKA is programmed from Vref (~2.5V) up to 36V by external resistors, requires a minimum regulating cathode current Imin of 0.4-1mA and is rated for a recommended continuous cathode current of 1mA to 100mA, with absolute maximum ratings of 37V cathode voltage and -100mA to 150mA cathode current. |
| 2 | ANODE | output | Common pin (anode, A), normally connected to ground/circuit common; provides the return path for the cathode current and is the reference node for the external feedback resistor divider. |
| 3 | REF | input | Reference/threshold input pin (measured relative to the common anode) that is internally compared to the device's ~2.5V bandgap reference; must be supplied with a reference input current of at least a few µA (typ. 2µA, max 4µA at IKA=10mA) and cannot be left floating, with an absolute maximum reference input current range of -0.05mA to 10mA. |

## Key specifications

| Parameter | Value |
|---|---|
| Manufacturer | Texas Instruments |
| Package | TO-92-3 |
| 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 voltage | Vref | 2440 | 2495 | 2550 | mV | VKA = Vref, IKA = 10mA | 8 |
| Reference input voltage deviation over temperature range (all devices other than SOT23-3 and TL432) | VI(dev) |  | 5 | 50 | mV | VKA = Vref, IKA = 10mA | 8 |
| Ratio of change in reference voltage to change in cathode voltage | ΔVref/ΔVKA |  | -1.4 | -2.7 | mV/V | IKA = 10mA; ΔVKA = 10V - Vref | 8 |
| Ratio of change in reference voltage to change in cathode voltage | ΔVref/ΔVKA |  | -1 | -2 | mV/V | IKA = 10mA; ΔVKA = 36V - 10V | 8 |
| Reference input current | Iref |  | 2 | 4 | µA | IKA = 10mA, R1 = 10kΩ, R2 = ∞ | 8 |
| Reference input current deviation over temperature range | II(dev) |  | 0.8 | 2.5 | µA | IKA = 10mA, R1 = 10kΩ, R2 = ∞ | 8 |
| Minimum cathode current for regulation | Imin |  | 0.4 | 1 | mA | VKA = Vref | 8 |
| Off-state cathode current | Ioff |  | 0.1 | 1 | µA | VKA = 36V, Vref = 0 | 8 |
| Dynamic impedance | /ZKA/ |  | 0.2 | 0.5 | Ω | VKA = Vref, f ≤ 1kHz, IKA = 1mA to 100mA | 8 |
| Cathode voltage | VKA |  |  | 36 | V |  | 6 |
| Continuous cathode current range | IKA | 1 |  | 100 | mA |  | 6 |
| Operating free-air temperature range (TL43xxI) | TA | -40 |  | 85 | ℃ | Natural air convection; TL43xxI | 6 |
| Cathode voltage | VKA |  |  | 37 | V |  | 6 |
| Continuous cathode current range | IKA | -100 |  | 150 | mA |  | 6 |
| Reference input current | II(ref) | -0.05 |  | 10 | mA |  | 6 |
| Operating junction temperature range | TJ |  |  | 150 | °C |  | 6 |
| Storage temperature range | Tstg | -65 |  | 150 | °C |  | 6 |
| Junction-to-ambient thermal resistance (LP package, TO-92) | RθJA |  | 140 |  | °C/W | LP (3-pin) package | 6 |
| Junction-to-case (top) thermal resistance (LP package, TO-92) | RθJC(top) |  | 55 |  | °C/W | LP (3-pin) package | 6 |

## CAD (KiCad official)

- Symbol: `TL431ILPR`
- Footprint: `Package_TO_SOT_THT:TO-92_Inline`
- 3D model: TO-92-3 (KiCad packages3D, STEP)
- 3D model files: `tl431ilpr-etched.step` / `tl431ilpr-etched.glb` carry the MPN laser-etched on the die in a toggleable `Adom.LaserEtch` group (Fusion-ready); `tl431ilpr.step` / `tl431ilpr.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 2026-09-23, 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 0.2`, primary `claude-haiku-4-5-20251001` (text), consensus `claude-sonnet-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/tl431ilpr-datasheet.pdf)