# LM4040D20IDBZT

**Texas Instruments** · Voltage Reference · SOT-23

LM4040D20IDBZT from Texas Instruments, in a SOT-23. 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 | Parallel current/voltage input; the regulated reverse breakdown voltage (VZ = 2.048 V) is developed between cathode and anode, and cathode current IZ must stay within the datasheet range (IZ,min to 15 mA recommended, 25 mA absolute maximum). |
| 2 | ANODE | output | General-purpose pin, typically grounded, and the reference for the regulated voltage on the cathode. |
| 3 | * | input | Must be left floating or connected to the anode (pin 2), because a parasitic Schottky diode exists between pins 2 and 3 of the SOT-23 package; TI recommends connecting it to the anode in applications with high EMI or significant high-frequency switching noise. |

## Key specifications

| Parameter | Value |
|---|---|
| Manufacturer | Texas Instruments |
| Package | SOT-23 |
| 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 |
|---|---|---|---|---|---|---|---|
| Reverse breakdown voltage tolerance | ΔVZ | -20 |  | 20 | mV | IZ = 100μA, 25°C | 7 |
| Reverse breakdown voltage tolerance | ΔVZ | -40 |  | 40 | mV | IZ = 100μA, full range TA = -40°C to 85°C | 7 |
| Minimum cathode current | IZ,min | 45 | 75 |  | μA | 25°C | 7 |
| Minimum cathode current | IZ,min |  |  | 80 | μA | full range TA = -40°C to 85°C | 7 |
| Average temperature coefficient of reverse breakdown voltage | αVZ | -20 |  | 20 | ppm/°C | IZ = 10mA, 25°C | 7 |
| Average temperature coefficient of reverse breakdown voltage | αVZ | -15 |  | 15 | ppm/°C | IZ = 1mA, 25°C | 7 |
| Average temperature coefficient of reverse breakdown voltage | αVZ | -150 |  | 150 | ppm/°C | full range TA = -40°C to 85°C | 7 |
| Reverse breakdown voltage change with cathode current |  |  | 0.3 | 1 | mV | IZ,min < IZ < 1mA, 25°C | 7 |
| Reverse breakdown voltage change with cathode current |  |  |  | 1.2 | mV | IZ,min < IZ < 1mA, full range TA = -40°C to 85°C | 7 |
| Reverse breakdown voltage change with cathode current |  |  | 2.5 | 8 | mV | 1mA < IZ < 15mA, 25°C | 7 |
| Reverse breakdown voltage change with cathode current |  |  |  | 10 | mV | 1mA < IZ < 15mA, full range TA = -40°C to 85°C | 7 |
| Reverse dynamic impedance | ZZ |  | 0.3 | 1.1 | Ω | IZ = 1mA, f = 120Hz, IAC = 0.1IZ, 25°C | 7 |
| Cathode current | IZ |  |  | 15 | mA |  | 5 |
| Operating free-air temperature (LM4040xxxI) | TA | -40 |  | 85 | °C | LM4040xxxI | 5 |
| Continuous cathode current | IZ | -10 |  | 25 | mA |  | 5 |
| Operating virtual junction temperature | TJ |  |  | 150 | °C |  | 5 |
| Storage temperature range | Tstg | -65 |  | 150 | °C |  | 5 |
| Reverse breakdown voltage | VZ |  | 2.048 |  | V | IZ = 100μA, 25°C | 7 |
| Wideband noise | eN |  | 35 |  | μVRMS | IZ = 100μA, 10Hz ≤ f ≤ 10kHz, 25°C | 7 |
| Long-term stability of reverse breakdown voltage |  |  | 120 |  | ppm | t = 1000 h, TA = 25°C ± 0.1°C, IZ = 100μA | 7 |
| Thermal hysteresis | VHYST |  | 0.08 |  | % | ΔTA = -40°C to 125°C | 7 |
| Junction-to-ambient thermal resistance | RθJA |  | 206 |  | °C/W | DBZ 3-pin package | 5 |

## CAD (KiCad official)

- Symbol: `LM4040D20IDBZT`
- Footprint: `Package_TO_SOT_SMD:SOT-23`
- 3D model: SOT-23 (KiCad packages3D, STEP)
- 3D model files: `lm4040d20idbzt-etched.step` / `lm4040d20idbzt-etched.glb` carry the MPN laser-etched on the die in a toggleable `Adom.LaserEtch` group (Fusion-ready); `lm4040d20idbzt.step` / `lm4040d20idbzt.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/lm4040) (62 pp, sha256 `68faec55d71e5cd5`, retrieved 2026-10-10, 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-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/lm4040d20idbzt-datasheet.pdf)