# U3211

**UNI SEMIC** · AC-DC Controllers And Regulators · SOP-8

U3211 from UNI SEMIC, 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 | VDD | power_in | Chip positive supply pin; also serves as output voltage feedback reference when FB pin floats; typical application requires 100nF bypass capacitor on this pin. |
| 2 | GND | power_in | Chip reference ground. |
| 3 | FB | input | Feedback input pin for output voltage regulation; when this pin floats, default output voltage is 12V. |
| 4 | CS | output | Peak current detection output pin for inductor peak current monitoring and cycle-by-cycle current limiting. |
| 5 | Drain | output | Internal high voltage MOSFET drain; operating voltage range −0.3 V to 650 V, rated breakdown voltage 650 V, static on-resistance 4.5 Ω. |
| 6 | Drain | output | Internal high voltage MOSFET drain; operating voltage range −0.3 V to 650 V, rated breakdown voltage 650 V, static on-resistance 4.5 Ω. |
| 7 | Drain | output | Internal high voltage MOSFET drain; operating voltage range −0.3 V to 650 V, rated breakdown voltage 650 V, static on-resistance 4.5 Ω. |
| 8 | Drain | output | Internal high voltage MOSFET drain; operating voltage range −0.3 V to 650 V, rated breakdown voltage 650 V, static on-resistance 4.5 Ω. |

## Key specifications

| Parameter | Value |
|---|---|
| Manufacturer | UNI SEMIC |
| Package | SOP-8 |
| Category | Power Management (PMIC) |
| Pins | 8 |

## CAD (KiCad official)

- Symbol: `U3211`
- Footprint: `Package_SO:SOIC-8_3.9x4.9mm_P1.27mm`
- 3D model: SOP-8 (KiCad packages3D, STEP)
- 3D model files: `u3211-etched.step` / `u3211-etched.glb` carry the MPN laser-etched on the die in a toggleable `Adom.LaserEtch` group (Fusion-ready); `u3211.step` / `u3211.glb` are the bare package body.

## Provenance

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

- **Datasheet:** [UNI SEMIC datasheet](https://jlcpcb.com/api/file/downloadByFileSystemAccessId/8604437574182322176) (10 pp, sha256 `ebcf7302fc1b0f4a`, retrieved 2026-09-18, 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 0.2`, primary `claude-haiku-4-5-20251001` (text), consensus `claude-sonnet-4-6` (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/u3211-datasheet.pdf)