# DS8921ATMX

**Texas Instruments** · RS-485 / RS-422 ICs · SOIC-8

DS8921ATMX from Texas Instruments, in a SOIC-8. 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 | VCC | power_in | Power supply pin; rated 5 V with operating range 4.5 to 5.5 V |
| 2 | RO | output | Receiver output pin; TTL-compatible with VOH = 2.5 V minimum, VOL = 0.5 V maximum |
| 3 | DI | input | TTL/CMOS-compatible driver input; VIH = 2.0 V, VIL = 0.8 V |
| 4 | GND | power_in | Power ground pin |
| 5 | DO- | output | Inverting differential driver output; VOH = 2.5 V minimum, VOL = 0.5 V maximum |
| 6 | DO+ | output | Non-inverting differential driver output; VOH = 2.5 V minimum, VOL = 0.5 V maximum |
| 7 | RI- | input | Inverting differential receiver input; ±200 mV sensitivity over ±7 V common-mode range |
| 8 | RI+ | input | Non-inverting differential receiver input; ±200 mV sensitivity over ±7 V common-mode range |

## Key specifications

| Parameter | Value |
|---|---|
| Manufacturer | Texas Instruments |
| Package | SOIC-8 |
| Category | Interface |
| Pins | 8 |

## CAD (KiCad official)

- Symbol: `DS8921ATMX`
- Footprint: `Package_SO:SOIC-8_3.9x4.9mm_P1.27mm`
- 3D model: SOIC-8 (KiCad packages3D, STEP)
- 3D model files: `ds8921atmx-etched.step` / `ds8921atmx-etched.glb` carry the MPN laser-etched on the die in a toggleable `Adom.LaserEtch` group (Fusion-ready); `ds8921atmx.step` / `ds8921atmx.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/ds8921atmx.pdf) (22 pp, sha256 `0be14ebc915d205b`, 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/ds8921atmx-datasheet.pdf)