# DRV421RTJR

**Texas Instruments** · Current Sensors · QFN-20-EP(4x4)

DRV421RTJR from Texas Instruments, in a QFN-20-EP(4x4). 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 | GSEL0 | input | Gain and bandwidth selection input 0. |
| 2 | RSEL1 | input | Voltage reference mode selection input 1. |
| 3 | RSEL0 | input | Voltage reference mode selection input 0. |
| 4 | REFOUT | output | Voltage reference output, referenced to GND; the datasheet recommends a low-impedance, star-type connection to GND. |
| 5 | REFIN | input | Common-mode reference input for the shunt sense amplifier. |
| 6 | VOUT | output | Shunt sense amplifier output. |
| 7 | GND | power_in | Ground reference; connect all GND pins to a local ground plane. |
| 8 | VDD | power_in | Supply voltage, 3.0 V to 5.5 V; decouple both VDD pins with 1-µF ceramic capacitors placed as close as possible to the device. |
| 9 | VDD | power_in | Supply voltage, 3.0 V to 5.5 V; decouple both VDD pins with 1-µF ceramic capacitors placed as close as possible to the device. |
| 10 | GND | power_in | Ground reference; connect all GND pins to a local ground plane. |
| 11 | ICOMP2 | output | Output 2 of compensation coil driver. |
| 12 | ICOMP1 | output | Output 1 of compensation coil driver. |
| 13 | AINP | input | Noninverting input of shunt sense amplifier. |
| 14 | AINN | input | Inverting input of shunt sense amplifier. |
| 15 | OR | output | Shunt sense amplifier overrange indicator; open-drain, active-low output. |
| 16 | GND | power_in | Ground reference; connect all GND pins to a local ground plane. |
| 17 | GND | power_in | Ground reference; connect all GND pins to a local ground plane. |
| 18 | DEMAG | input | Degauss control input. |
| 19 | ER | output | Error flag; open-drain, active-low output. |
| 20 | GSEL1 | input | Gain and bandwidth selection input 1. |
| 21 | PowerPAD | passive | Exposed pad (from the footprint; not named in the datasheet pin table). |

## Key specifications

| Parameter | Value |
|---|---|
| Manufacturer | Texas Instruments |
| Package | QFN-20-EP(4x4) |
| Category | Magnetic Sensors |
| Pins | 21 |

## CAD (KiCad official)

- Symbol: `DRV421RTJR`
- Footprint: `Package_DFN_QFN:QFN-20-1EP_4x4mm_P0.5mm_EP2.5x2.5mm`
- 3D model: QFN-20-EP(4x4) (KiCad packages3D, STEP)
- 3D model files: `drv421rtjr-etched.step` / `drv421rtjr-etched.glb` carry the MPN laser-etched on the die in a toggleable `Adom.LaserEtch` group (Fusion-ready); `drv421rtjr.step` / `drv421rtjr.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/drv421) (44 pp, sha256 `dd983581ec2e1574`, retrieved 2026-10-11, 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/drv421rtjr-datasheet.pdf)