# 1SMB5952BT3G

**onsemi** · Zener Diodes · SMB

1SMB5952BT3G from onsemi, 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 | Cathode | passive | Cathode end of the Zener diode, indicated by the polarity band; reverse Zener voltage VZ is 123.5 V min, 130 V nom, 136.5 V max at IZT = 2.9 mA for the 1SMB5952BT3G. |
| 2 | Anode | passive | Anode end of the Zener diode; forward voltage VF is 1.5 V max at IF = 200 mA(dc). |

## Key specifications

| Parameter | Value |
|---|---|
| Manufacturer | onsemi |
| Package | SMB |
| Category | Diodes |
| 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 |
|---|---|---|---|---|---|---|---|
| Zener Voltage | VZ | 123.5 | 130 | 136.5 | V | @ IZT = 2.9 mA, TL = 30°C | 3 |
| Maximum Zener Impedance | ZZT |  |  | 450 | Ω | @ IZT = 2.9 mA | 3 |
| Maximum Zener Impedance at knee | ZZK |  |  | 5000 | Ω | @ IZK = 0.25 mA | 3 |
| Reverse Leakage Current | IR |  |  | 1 | µA | @ VR = 98.8 V | 3 |
| Maximum DC Zener Current | IZM |  |  | 11 | mA |  | 3 |
| Forward Voltage | VF |  |  | 1.5 | V | @ IF = 200 mA(dc) | 3 |
| Zener Voltage Tolerance |  | -5 |  | 5 | % | Type numbers listed indicate a tolerance of ±5% | 3 |
| Test Current | IZT |  | 2.9 |  | mA |  | 3 |
| Maximum Steady State Power Dissipation (lead) | PD |  |  | 3 | W | @ TL = 75°C, measured at zero lead length | 1 |
| Power Derating above 75°C |  |  |  | 40 | mW/°C | Derate above 75°C | 1 |
| Maximum Steady State Power Dissipation (ambient) | PD |  |  | 550 | mW | @ TA = 25°C, FR-4 board, recommended footprint | 1 |
| Power Derating above 25°C |  |  |  | 4.4 | mW/°C | Derate above 25°C | 1 |
| Operating and Storage Temperature Range | TJ, Tstg | -65 |  | 150 | °C |  | 1 |
| Thermal Resistance, Junction-to-Lead | RθJL |  | 25 |  | °C/W |  | 1 |
| Thermal Resistance, Junction-to-Ambient | RθJA |  | 226 |  | °C/W | FR-4 board, recommended footprint | 1 |
| Maximum Lead Temperature for Soldering |  |  |  | 260 | °C | 10 seconds | 1 |

## CAD (KiCad official)

- Symbol: `1SMB5952BT3G`
- Footprint: `Diode_SMD:D_SMB`
- 3D model: SMB (KiCad packages3D, STEP)
- 3D model files: `1smb5952bt3g-etched.step` / `1smb5952bt3g-etched.glb` carry the MPN laser-etched on the die in a toggleable `Adom.LaserEtch` group (Fusion-ready); `1smb5952bt3g.step` / `1smb5952bt3g.glb` are the bare package body.

## Provenance

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

- **Datasheet:** [onsemi datasheet](https://www.onsemi.com/pdf/datasheet/1smb5952bt3-d.pdf) (6 pp, sha256 `e95f4deeabd8ea97`, retrieved 2026-10-22, tier: manufacturer)
- **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/1smb5952bt3g-datasheet.pdf)