# COS8221ARZ

**COSINE** · Instrumentation Amplifiers · SOP-8

COS8221ARZ from COSINE, in a SOP-8. Pinout and pin descriptions extracted from the manufacturer datasheet by ds2sf; symbol, footprint, and 3D from KiCad-official CAD.

## Pinout

| Pin | Name | Type | Function |
|---|---|---|---|
| 1 | VIN- | input | Negative (inverting) analog input to the instrumentation amplifier. Input terminals are diode-clamped to the supply rails; signals swinging more than 0.5V beyond the rails should be current-limited to <=10mA. Common-mode voltage range: -Vs+1.9V to +Vs-1.2V. |
| 2 | RG | passive | Gain-setting pin. Connect an external gain resistor RG between pins 2 and 3 to set gain per G = 1 + 49.4kΩ/RG. Leave open (NC) for unity gain. |
| 3 | RG | passive | Gain-setting pin. Connect an external gain resistor RG between pins 2 and 3 to set gain per G = 1 + 49.4kΩ/RG. Leave open (NC) for unity gain. |
| 4 | VIN+ | input | Positive (non-inverting) analog input to the instrumentation amplifier. Input terminals are diode-clamped to the supply rails; signals swinging more than 0.5V beyond the rails should be current-limited to <=10mA. Common-mode voltage range: -Vs+1.9V to +Vs-1.2V. |
| 5 | -VS | power_in | Negative supply rail. Operating range -2.25V to -18V (dual-supply operation) or ground for single-supply operation. Bypass to ground with a 0.1µF ceramic capacitor placed close to the pin. |
| 6 | REF | input | Output-stage reference input; sets the output DC level. Must be driven by a low-impedance source (or tied to ground) to preserve CMRR; ~8Ω of series resistance degrades CMR to ~80dB. |
| 7 | VOUT | output | Amplifier output. Output swing extends to +Vs-1.1V (high) and -Vs+0.9V (low); rated output current ±10mA (short-circuit current typ ±24mA). |
| 8 | +VS | power_in | Positive supply rail. Operating range +2.25V to +18V (dual-supply) or +4.5V to +36V (single-supply). Bypass with a 0.1µF ceramic capacitor placed close to the pin; a 2.2µF tantalum may be added for improved performance. |

## Key specifications

| Parameter | Value |
|---|---|
| Manufacturer | COSINE |
| Package | SOP-8 |
| Category | Amplifiers/Comparators |
| Pins | 8 |

## Ordering variants

Same part, different packaging or reel option.

- `COS8221ARZ`
- `COS8221BRZ`
- `COS8221MR`
- `COS8221DT`

## CAD (KiCad official)

- Symbol: `COS8221ARZ`
- Footprint: `Package_SO:SOIC-8_3.9x4.9mm_P1.27mm`
- 3D model: SOP-8 (KiCad packages3D, STEP)
- 3D model files: `cos8221arz-etched.step` / `cos8221arz-etched.glb` carry the MPN laser-etched on the die in a toggleable `Adom.LaserEtch` group (Fusion-ready); `cos8221arz.step` / `cos8221arz.glb` are the bare package body.

## Provenance

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

- **Datasheet:** [COSINE datasheet](https://jlcpcb.com/api/file/downloadByFileSystemAccessId/8590234192907960320) (8 pp, sha256 `0e71b764a438c162`, retrieved 2026-08-17, tier: lcsc)
- **Extractor:** `ds2sf` (Claude). Every pin and dimension is cited to a datasheet page; it refuses to fabricate.
- **CAD:** KiCad official libraries (CC-BY-SA 4.0).

[Datasheet PDF](docs/cos8221arz-datasheet.pdf)