# BQ21040DBVT

**Texas Instruments** · Battery Management · SOT-23-6

BQ21040DBVT from Texas Instruments, in a SOT-23-6. 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 | TS | input | Temperature sense terminal connected to NTC thermistor in battery pack; floating or high voltage enters TTDM mode, low disables IC, or use fixed 10kΩ resistor to VSS if thermistor not needed. |
| 2 | OUT | output | Battery charging output terminal supporting system load; 1μF to 10μF bypass capacitor expected. |
| 3 | CHG | tri_state | Open drain charge status output; low (FET on) during first charge cycle, high impedance (FET off) when charge complete or no charging. |
| 4 | ISET | input | Fast-charge current programming input; external resistor to VSS from 10.8kΩ (50mA) to 675Ω (800mA) defines fast charge current. |
| 5 | GND | power_in | Ground terminal and thermal pad connection to PCB ground plane. |
| 6 | VIN | power_in | Input power supply from AC adapter or USB port; 3.5V to 28V operating range with 1μF to 10μF bypass capacitor to VSS recommended. |

## Key specifications

| Parameter | Value |
|---|---|
| Manufacturer | Texas Instruments |
| Package | SOT-23-6 |
| Category | Power Management (PMIC) |
| Pins | 6 |

## CAD (KiCad official)

- Symbol: `BQ21040DBVT`
- Footprint: `Package_TO_SOT_SMD:SOT-23-6`
- 3D model: SOT-23-6 (KiCad packages3D, STEP)
- 3D model files: `bq21040dbvt-etched.step` / `bq21040dbvt-etched.glb` carry the MPN laser-etched on the die in a toggleable `Adom.LaserEtch` group (Fusion-ready); `bq21040dbvt.step` / `bq21040dbvt.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/bq21040.pdf) (31 pp, sha256 `66c454e4978439d2`, retrieved 2026-09-24, tier: manufacturer)
- **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/bq21040dbvt-datasheet.pdf)