# REF3440SQDBVRQ1

**Texas Instruments** · Voltage Reference · SOT-23-5

REF3440SQDBVRQ1 from Texas Instruments, in a SOT-23-5. 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 | NC | unconnected | Test pin per the datasheet, specified to be connected from 0 V to 18 V, so it is not a true no-connect. |
| 2 | GND | power_in | Ground connection for the reference. |
| 3 | IN | power_in | Input supply voltage connection; absolute maximum is -0.3 V to 13 V, and VIN must be VOUT + VDO up to 12 V. |
| 4 | OUT | output | Reference voltage output connection, with output current limited to ±10 mA and short-circuit current limited to 18 mA. |
| 5 | NIC | unconnected | No internal connection. |

## Key specifications

| Parameter | Value |
|---|---|
| Manufacturer | Texas Instruments |
| Package | SOT-23-5 |
| Category | Power Management (PMIC) |
| Pins | 5 |

## Electrical characteristics

Limits as printed in the datasheet (page.json `metadata.characteristics` carries them as data).

| Parameter | Symbol | Min | Typ | Max | Unit | Conditions | Page |
|---|---|---|---|---|---|---|---|
| Output voltage accuracy |  | -0.05 |  | 0.05 | % | TA = 25°C | 6 |
| Line regulation | ΔVO/ΔVIN |  | 2 | 15 | ppm/V | VIN = VOUT + VDO (footnote 2, VDO = 50mV) to 12V | 6 |
| Load regulation, sourcing | ΔVO/ΔIL |  | 20 | 30 | ppm/mA | IL = 0mA to 10mA, VIN = VOUT + VDO (footnote 3, VDO = 500mV) | 6 |
| Load regulation, sinking | ΔVO/ΔIL |  | 60 | 98 | ppm/mA | IL = 0mA to -10mA, VIN = VOUT + VDO (footnote 3, VDO = 500mV) | 6 |
| Capacitive load stable range | CL | 0.1 |  | 10 | µF |  | 6 |
| Input voltage | VIN |  |  | 12 | V | Minimum is VOUT + VDO (expression, not a numeric limit) | 7 |
| Output current capability | IL | -10 |  | 10 | mA | VIN = VOUT + VDO to 12V | 7 |
| Dropout voltage (row 1, value 50 mV) | VDO |  | 50 |  | mV | IL = 0mA | 7 |
| Dropout voltage (max at IL = 0mA) | VDO |  |  | 100 | mV | IL = 0mA | 7 |
| Dropout voltage (max at IL = 10mA) | VDO |  |  | 500 | mV | IL = 10mA | 7 |
| Quiescent current, operating mode | IQ |  | 72 | 95 | µA | Operating mode | 7 |
| Short-circuit current | ISC |  | 18 | 22 | mA | TA = 25°C, VOUT = 0V | 7 |
| Recommended input voltage | IN |  |  | 12 | V | Minimum is VOUT + VDO (expression, not a numeric limit) | 5 |
| Recommended output current | IL | -10 |  | 10 | mA |  | 5 |
| Recommended operating ambient temperature | TA | -40 | 25 | 125 | °C |  | 5 |
| Absolute maximum input voltage | IN | -0.3 |  | 13 | V |  | 5 |
| Absolute maximum output voltage | VOUT | -0.3 |  | 5.5 | V |  | 5 |
| Output short-circuit current |  |  |  | 20 | mA |  | 5 |
| Absolute maximum operating temperature range | TA | -55 |  | 150 | °C | Free-air, natural convection | 5 |
| Storage temperature range | Tstg | -65 |  | 170 | °C |  | 5 |
| Output voltage | VOUT |  | 4.096 |  | V | REF3440Q1 variant | 7 |
| Output voltage temperature coefficient |  |  | 2.5 | 6 | ppm/°C | Box method (see temperature drift section) | 6 |
| Integrated wideband noise | en |  | 24 |  | µVrms | 10Hz ≤ f ≤ 10kHz | 6 |
| Low-frequency noise, peak-to-peak | enp-p |  | 3.8 |  | µVp-p/V | 0.1Hz ≤ f ≤ 10Hz (REF3440-Q1) | 6 |
| Output voltage noise density | en |  | 0.2 |  | ppm/√Hz | f = 1kHz (REF3440-Q1) | 6 |
| Long-term stability, 0h to 1000h (DBV package) |  |  | 25 |  | ppm | 35°C, 0h to 1000h | 6 |
| Long-term stability, 1000h to 2000h (DBV package) |  |  | 10 |  | ppm | 35°C, 1000h to 2000h | 6 |
| Output voltage thermal hysteresis, cycle 1 (DBV package) |  |  | 30 |  | ppm | 25°C, -40°C, 125°C, 25°C cycle 1 | 6 |
| Output voltage thermal hysteresis, cycle 2 (DBV package) |  |  | 10 |  | ppm | 25°C, -40°C, 125°C, 25°C cycle 2 | 6 |
| Thermal resistance, junction-to-ambient (DBV 5-pin) | RθJA |  | 122.6 |  | °C/W |  | 5 |
| Thermal resistance, junction-to-case (top) (DBV 5-pin) | RθJC(top) |  | 80.2 |  | °C/W |  | 5 |
| Thermal resistance, junction-to-board (DBV 5-pin) | RθJB |  | 42 |  | °C/W |  | 5 |
| Junction-to-top characterization parameter (DBV 5-pin) | ΨJT |  | 23.2 |  | °C/W |  | 5 |
| Junction-to-board characterization parameter (DBV 5-pin) | ΨJB |  | 41.9 |  | °C/W |  | 5 |

## CAD (KiCad official)

- Symbol: `REF3440SQDBVRQ1`
- Footprint: `Package_TO_SOT_SMD:SOT-23-5`
- 3D model: SOT-23-5 (KiCad packages3D, STEP)
- 3D model files: `ref3440sqdbvrq1-etched.step` / `ref3440sqdbvrq1-etched.glb` carry the MPN laser-etched on the die in a toggleable `Adom.LaserEtch` group (Fusion-ready); `ref3440sqdbvrq1.step` / `ref3440sqdbvrq1.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/ref34-q1) (40 pp, sha256 `addb0b3508cd0c2e`, retrieved 2026-10-12, 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/ref3440sqdbvrq1-datasheet.pdf)