# CM1821B50

**iCM(创芯微)** · Voltage Regulators - Linear, Low Drop Out (LDO) Regulators · SOT-23-3

CM1821B50 from iCM(创芯微), in a SOT-23-3. 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 | GND | power_in | Ground reference pin for the regulator (datasheet lists it only as 地, ground); the absolute-maximum VIN-to-ground rating is -0.3 to 30 V. |
| 2 | VOUT | power_out | Regulated output, rated 2.5 V to 5.0 V fixed (this variant is the 5.0 V CM1821X50) with up to 150 mA output current and VOUT-to-ground limit of -0.3 to 6 V. |
| 3 | VIN | power_in | Input supply pin, rated up to 30 V (VIN-to-ground limit -0.3 to 30 V), with 600 mV typical dropout at 100 mA. |

## Key specifications

| Parameter | Value |
|---|---|
| Manufacturer | iCM(创芯微) |
| Package | SOT-23-3 |
| Category | Power Management (PMIC) |
| Pins | 3 |

## Electrical characteristics

Limits as printed in the datasheet (page.json `metadata.characteristics` carries them as data).

| Parameter | Symbol | Min | Typ | Max | Unit | Conditions | Page |
|---|---|---|---|---|---|---|---|
| Output voltage accuracy (VOUT, 5.0 V version) | VOUT | -1 |  | 1 | % | VIN=12V，IOUT=10mA | 4 |
| Quiescent current | IGND |  | 3 | 6 | µA | VIN=12V，空载 | 4 |
| Load regulation | ΔVOUT |  | 30 | 60 | mV | 1mA≤IOUT≤100mA | 4 |
| Input capacitor Cin (external) | Cin | 1 | 10 | 22 | µF |  | 2 |
| Output capacitor Cout (external) | Cout | 1 | 10 | 10 | µF |  | 2 |
| VIN to GND withstand voltage | VIN | -0.3 |  | 30 | V |  | 3 |
| VOUT to GND withstand voltage | VOUT | -0.3 |  | 6 | V |  | 3 |
| VOUT to VIN withstand voltage |  | -30 |  | 0.3 | V |  | 3 |
| Operating ambient temperature |  | -40 |  | 85 | ℃ |  | 3 |
| Storage temperature |  | -40 |  | 150 | ℃ |  | 3 |
| Operating junction temperature |  |  |  | 150 | ℃ |  | 3 |
| Thermal resistance, SOT23-3 |  |  |  | 380 | ℃/W |  | 3 |

## CAD (KiCad official)

- Symbol: `CM1821B50`
- Footprint: `Package_TO_SOT_SMD:SOT-23-3`
- 3D model: SOT-23-3 (KiCad packages3D, STEP)
- 3D model files: `cm1821b50-etched.step` / `cm1821b50-etched.glb` carry the MPN laser-etched on the die in a toggleable `Adom.LaserEtch` group (Fusion-ready); `cm1821b50.step` / `cm1821b50.glb` are the bare package body.

## Provenance

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

- **Datasheet:** [iCM(创芯微) datasheet](https://jlcpcb.com/api/file/downloadByFileSystemAccessId/8603386744419610624) (10 pp, sha256 `19594f69e73ad482`, retrieved 2026-11-08, 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-5-5` (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/cm1821b50-datasheet.pdf)