# MMBTH10

**UMW (Youtai Semiconductor)** · NPN RF transistor · SOT-23

UMW MMBTH10 NPN transistor in SOT-23 for VHF and UHF amplifiers, mixers and oscillators: 650 MHz transition frequency, 25 V, 50 mA. Marking 3EM.

## Verification

A person checks each page against its datasheet and signs it off here; the badge turns amber if a checked file changes.

::adom-verified{src="/adom/mmbth10/render/verification.json"}

## Pinout

| Pin | Name | Type | Function |
|---|---|---|---|
| 1 | B | input | Base (datasheet p.1). |
| 2 | E | passive | Emitter. |
| 3 | C | passive | Collector. |

## Key specifications

| Parameter | Value | Source |
|---|---|---|
| Collector-emitter voltage | 25 V | Datasheet p.1 |
| Collector-base voltage | 30 V | Datasheet p.1 |
| Emitter-base voltage | 3 V | Datasheet p.1 |
| Collector current | 50 mA | Datasheet p.1 |
| Power dissipation | 225 mW | Datasheet p.1 |
| DC current gain | 60 min at VCE = 10 V, IC = 4 mA | Datasheet p.1 |
| Transition frequency | 650 MHz | Datasheet p.1 |
| Collector output capacitance | 0.7 pF max | Datasheet p.1 |
| Marking | 3EM | Datasheet p.1 |

## Ordering

| Distributor | Part number | Note |
|---|---|---|
| LCSC / JLCPCB | [C545531](https://www.lcsc.com/product-detail/C545531.html) | JLC Extended part, 8,358 in stock on 2026-10-08 |
| Mouser | not listed | no listing for this manufacturer's part (searched 2026-10-08; the same number from onsemi was not counted) |
| DigiKey | not listed | no listing for this manufacturer's part (searched 2026-10-08; the same number from onsemi was not counted) |

## CAD

| File | What it is |
|---|---|
| `mmbth10.kicad_sym` | KiCad symbol, with MPN, manufacturer and distributor numbers as properties |
| `mmbth10.kicad_mod` | KiCad footprint: `Package_TO_SOT_SMD:SOT-23`, KiCad official, CC-BY-SA 4.0 |
| `mmbth10.step` / `mmbth10.glb` | 3D model, Z-up, seated on z = 0: KiCad packages3D (tag 10.0.6), SOT-23.step |
| `mmbth10-etched.step` / `mmbth10-etched.glb` | The same model with the part number laser-etched on top as a separate, toggleable `Adom.LaserEtch` group (a virtual identification aid, not the maker's real marking) |
| `mmbth10.lbr` | Fusion 360 / EAGLE library: one deviceset, each with its own MPN, manufacturer and LCSC / Mouser / DigiKey attributes |
| `altium/Adom_mmbth10.SchLib` / `.PcbLib` | Altium library pair (adom-lbr, no Altium needed): symbol and footprint with the 3D body, parameters carry the part numbers; `altium/*.adom-lbr.json` is the canonical hub each was built from |

## Provenance

- **Datasheet:** [docs/mmbth10-datasheet.pdf](docs/mmbth10-datasheet.pdf), sha256 `2a9450e4a971155a`, retrieved 2026-10-08 from LCSC
- **Specs:** each row names its source: the manufacturer datasheet (with page) or the LCSC parametric listing (retrieved 2026-10-08).
- **Distributor numbers:** looked up 2026-10-08 with adom-parts-search (Mouser, DigiKey, JLCPCB), exact part number and manufacturer only.
- **CAD:** footprint `Package_TO_SOT_SMD:SOT-23`; 3D: KiCad packages3D (tag 10.0.6), SOT-23.step.

## Related

- Used on the [AM/FM Receiver Molecule](https://wiki.adom.inc/adom/amfm-receiver-molecule).