# ASMBJ51CA

**PTTC(Polytronics Tech)** · ESD And Surge Protection (TVS/ESD) · SMB

ASMBJ51CA from PTTC(Polytronics Tech), in a SMB. 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 | A1 | passive | Bi-directional TVS terminal 1 (no cathode band), interchangeable with terminal 2, VR 51.0 V stand-off and VBR 56.7-62.7 V at 1 mA. |
| 2 | A2 | passive | Bi-directional TVS terminal 2 (no cathode band), interchangeable with terminal 1, maximum clamping voltage 82.4 V at IPP 7.3 A. |

## Key specifications

| Parameter | Value |
|---|---|
| Manufacturer | PTTC(Polytronics Tech) |
| Package | SMB |
| Category | Circuit Protection |
| Pins | 2 |

## Electrical characteristics

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

| Parameter | Symbol | Min | Typ | Max | Unit | Conditions | Page |
|---|---|---|---|---|---|---|---|
| Reverse Stand-Off Voltage | VR |  | 51 |  | V |  | 3 |
| Breakdown Voltage | VBR | 56.7 |  | 62.7 | V | @ IT = 1 mA | 3 |
| Maximum Clamping Voltage | VC |  |  | 82.4 | V | @ IPP = 7.3 A | 3 |
| Maximum Peak Pulse Current | IPP |  |  | 7.3 | A |  | 3 |
| Maximum Reverse Leakage | IR |  |  | 1 | A | @ VR | 3 |
| Peak Pulse Power Dissipation | PPPM | 600 |  |  | Watt | 10/1000s waveform | 1 |
| Steady State Power Dissipation | PM(AV) |  |  | 5 | Watt | TL = 75°C, lead lengths 0.375” (9.5mm) | 1 |
| Peak Forward Surge Current | IFSM |  |  | 100 | Amp | 8.3 ms single half sine wave superimposed on rated load | 1 |
| Operating Junction and Storage Temperature Range | TJ, TSTG | -55 |  | 150 | °C |  | 1 |
| VBR Voltage tolerance |  | -5 |  | 5 | % | Part code A | 1 |
| Test Current | IT |  | 1 |  | mA | VBR test | 3 |
| Reflow Peak Temperature |  |  |  | 260 | ºC | Lead free reflow | 5 |

## CAD (KiCad official)

- Symbol: `ASMBJ51CA`
- Footprint: `Diode_SMD:D_SMB`
- 3D model: SMB (KiCad packages3D, STEP)
- 3D model files: `asmbj51ca-etched.step` / `asmbj51ca-etched.glb` carry the MPN laser-etched on the die in a toggleable `Adom.LaserEtch` group (Fusion-ready); `asmbj51ca.step` / `asmbj51ca.glb` are the bare package body.

## Provenance

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

- **Datasheet:** [PTTC(Polytronics Tech) datasheet](docs/asmbj51ca-datasheet.pdf) (6 pp, sha256 `b85798a40e48d412`, retrieved 2026-10-22, tier: lcsc)
- **Extractor:** parts-factory `2.0.0` / `extract_pins 0.3`, primary `claude-sonnet-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/asmbj51ca-datasheet.pdf)