# ISO7721FDR

**Texas Instruments** · Digital Isolators · SOIC-8

ISO7721FDR 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 | VCC1 | power_in | Input supply voltage with operating range 2.25 V to 5.5 V. |
| 2 | OUTA | output | Channel A digital output with 100 Mbps data rate; output high voltage 4.8 V nominal (IOH = -4 mA), output low voltage 0.2 V to 0.4 V (IOL = 4 mA). |
| 3 | INB | input | Channel B digital input with high-level threshold 0.7 × VCCI and low-level threshold 0.3 × VCCI. |
| 4 | GND1 | power_in | Ground connection for input-side VCC1. |
| 5 | GND2 | power_in | Ground connection for output-side VCC2. |
| 6 | OUTB | output | Channel B digital output with 100 Mbps data rate; output high voltage 4.8 V nominal (IOH = -4 mA), output low voltage 0.2 V to 0.4 V (IOL = 4 mA). |
| 7 | INA | input | Channel A digital input with high-level threshold 0.7 × VCCI and low-level threshold 0.3 × VCCI. |
| 8 | VCC2 | power_in | Output supply voltage with operating range 2.25 V to 5.5 V. |

## Key specifications

| Parameter | Value |
|---|---|
| Manufacturer | Texas Instruments |
| Package | SOIC-8 |
| Category | Signal Isolation Devices |
| Pins | 8 |

## CAD (KiCad official)

- Symbol: `ISO7721FDR`
- Footprint: `Package_SO:SOIC-8_3.9x4.9mm_P1.27mm`
- 3D model: SOIC-8 (KiCad packages3D, STEP)
- 3D model files: `iso7721fdr-etched.step` / `iso7721fdr-etched.glb` carry the MPN laser-etched on the die in a toggleable `Adom.LaserEtch` group (Fusion-ready); `iso7721fdr.step` / `iso7721fdr.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/iso7721) (51 pp, sha256 `7158bdf150cc2c73`, retrieved 2026-10-05, 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-4-5-20251001` (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/iso7721fdr-datasheet.pdf)