# ST485ECDR-TD

**TDSEMIC** · RS-485 / RS-422 ICs · SOP-8

ST485ECDR-TD from TDSEMIC, in a SOP-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 | RO | output | Receiver output: RO is high when A is at least 200 mV above B and low when A is at least 200 mV below B, and it is high-impedance when RE is high. |
| 2 | RE | input | Receiver enable, active low; when RE is high the receiver output RO is high-impedance. |
| 3 | DE | input | Driver enable, active high; when DE is low the driver outputs are high-impedance, and when DE is high the device transmits (DE low with RE low puts it in receive mode). |
| 4 | DI | input | Driver data input: DI low drives A high and B low, and DI high drives the opposite. |
| 5 | GND | power_in | Ground, negative supply terminal. |
| 6 | A | bidirectional | Non-inverting receiver input and non-inverting driver output. |
| 7 | B | bidirectional | Inverting receiver input and inverting driver output. |
| 8 | VCC | power_in | Positive supply terminal. |

## Key specifications

| Parameter | Value |
|---|---|
| Manufacturer | TDSEMIC |
| Package | SOP-8 |
| Category | Interface |
| Pins | 8 |

## CAD (KiCad official)

- Symbol: `ST485ECDR-TD`
- Footprint: `Package_SO:SOIC-8_3.9x4.9mm_P1.27mm`
- 3D model: SOP-8 (KiCad packages3D, STEP)
- 3D model files: `st485ecdr-td-etched.step` / `st485ecdr-td-etched.glb` carry the MPN laser-etched on the die in a toggleable `Adom.LaserEtch` group (Fusion-ready); `st485ecdr-td.step` / `st485ecdr-td.glb` are the bare package body.

## Provenance

Data extracted from the manufacturer datasheet, not a distributor listing:

- **Datasheet:** [TDSEMIC datasheet](https://jlcpcb.com/api/file/downloadByFileSystemAccessId/8614113004451880960) (11 pp, sha256 `e0f1e059df77b64f`, retrieved 2026-10-09, 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-sonnet-5-5` (vision), consensus `claude-opus-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/st485ecdr-td-datasheet.pdf)