# RS121PXF

**Jiangsu RUNIC Tech** · Operational Amplifier · SOT23-5

RS121PXF from Jiangsu RUNIC Tech, in a SOT23-5. 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 | OUT | output | Op-amp output. Rail-to-rail output; short-circuit current limited to ±55 mA. Output swings within ~10-40 mV of each supply rail depending on load (10 kΩ / 2 kΩ). |
| 2 | V- | power_in | Negative (lowest) power supply. Connect to ground for single-supply operation or to negative rail for dual-supply. Vs = (V+) − (V−) must be between 2.6 V and 5.5 V (single-supply) or ±1.3 V to ±2.75 V (dual-supply); absolute max Vs = 7 V. |
| 3 | +IN | input | Positive (noninverting) input. Rail-to-rail input; common-mode range -0.2 V to +5.7 V at Vs = 5.5 V. Input bias current typ. ±1 pA (max ±10 pA). Input clamped to supply rails via diodes; limit external current to ≤10 mA when signals exceed rails by >0.5 V. |
| 4 | -IN | input | Negative (inverting) input. Rail-to-rail input; common-mode range -0.2 V to +5.7 V at Vs = 5.5 V. Input bias current typ. ±1 pA. Input clamped to supply rails via diodes; limit external current to ≤10 mA when signals exceed rails by >0.5 V. |
| 5 | V+ | power_in | Positive (highest) power supply. Operating range 2.6 V to 5.5 V (single-supply); absolute max Vs = (V+) − (V−) = 7 V. Quiescent current typ. 7.6 µA per amplifier (max 11 µA). |

## Key specifications

| Parameter | Value |
|---|---|
| Manufacturer | Jiangsu RUNIC Tech |
| Package | SOT23-5 |
| Category | Op-amp/Cmp |
| Pins | 5 |

## Ordering variants

Same part, different packaging or reel option.

- `RS121PXF`
- `RS121PXFXC5`
- `RS121PXFXK`
- `RS121PXFXM`
- `RS121PXFXP`
- `RS121PXFXQ`

## CAD (KiCad official)

- Symbol: `RS121PXF`
- Footprint: `Package_TO_SOT_SMD:SOT-23-5`
- 3D model: SOT23-5 (KiCad packages3D, STEP)
- 3D model files: `rs121pxf-etched.step` / `rs121pxf-etched.glb` carry the MPN laser-etched on the die in a toggleable `Adom.LaserEtch` group (Fusion-ready); `rs121pxf.step` / `rs121pxf.glb` are the bare package body.

## Provenance

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

- **Datasheet:** [Jiangsu RUNIC Tech datasheet](docs/rs121pxf-datasheet.pdf) (27 pp, sha256 `ad15de92c23081bf`, 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/rs121pxf-datasheet.pdf)