component
1KSMB39A
Public Made by Adomby adom
Littelfuse Electrostatic And Surge Protection (TVS/ESD), DO-214AA. Pinout cross-checked by two models against the datasheet, KiCad symbol/footprint/3D.
main
1KSMB39A
Littelfuse · Electrostatic And Surge Protection (TVS/ESD) · DO-214AA
1KSMB39A from Littelfuse, in a DO-214AA. 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 terminal of the unidirectional TVS diode, marked by the color band on the DO-214AA (SMB J-Bend) body; 1KSMB39A has VR 33.3V and VBR 37.1-41.0V at 1mA. |
| 2 | Anode | passive | Anode terminal of the unidirectional TVS diode, opposite the cathode band; 1KSMB39A has maximum clamping voltage 53.9V at 18.6A Ipp. |
Key specifications
| Parameter | Value |
|---|---|
| Manufacturer | Littelfuse |
| Package | DO-214AA |
| Category | TVS/Fuse/Board Level 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 |
|---|---|---|---|---|---|---|---|
| Breakdown Voltage | VBR | 37.1 | 41 | V | @ IT = 1 mA | 2 | |
| Reverse Stand-off Voltage | VR | 33.3 | V | 2 | |||
| Test Current | IT | 1 | mA | 2 | |||
| Maximum Clamping Voltage | VC | 53.9 | V | @ Ipp = 18.6 A | 2 | ||
| Maximum Peak Pulse Current | Ipp | 18.6 | A | 2 | |||
| Maximum Reverse Leakage | IR | 1 | µA | @ VR | 2 | ||
| Maximum Instantaneous Forward Voltage | VF | 3.5 | V | at 50A, unidirectional only | 1 | ||
| Peak Pulse Power Dissipation | PPPM | 1000 | W | TA=25ºC, 10/1000µs waveform | 1 | ||
| Power Dissipation on Infinite Heat Sink | PD | 5 | W | TL=50°C | 1 | ||
| Peak Forward Surge Current | IFSM | 120 | A | 8.3ms single half sine wave, unidirectional only | 1 | ||
| Operating Temperature Range | TJ | -65 | 150 | °C | 1 | ||
| Storage Temperature Range | TSTG | -65 | 175 | °C | 1 | ||
| Thermal Resistance Junction to Lead | RθJL | 20 | °C/W | Typical | 1 | ||
| Thermal Resistance Junction to Ambient | RθJA | 100 | °C/W | Typical | 1 | ||
| Breakdown Voltage Temperature Coefficient | αT | 0.1 | % | typical value | 1 |
Materials and finish
As the datasheet states them (page.json metadata.appearance; the 3D model's colours follow it).
| Part | Material | Colour / plating | Datasheet says | Page |
|---|---|---|---|---|
| contacts | tin | • Matte tin lead-free Plated • Available in breakdown | 1 |
CAD (KiCad official)
- Symbol:
1KSMB39A - Footprint:
Diode_SMD:D_SMB - 3D model: DO-214AA (KiCad packages3D, STEP)
- 3D model files:
1ksmb39a-etched.step/1ksmb39a-etched.glbcarry the MPN laser-etched on the die in a toggleableAdom.LaserEtchgroup (Fusion-ready);1ksmb39a.step/1ksmb39a.glbare the bare package body.
Provenance
Data extracted from the manufacturer datasheet, not a distributor listing:
- Datasheet: Littelfuse datasheet (6 pp, sha256
3a84dff49a0cb8e5, retrieved 2026-10-23, tier: lcsc) - Extractor: parts-factory
2.0.0/extract_pins 0.3, primaryclaude-sonnet-5-5(text), consensusclaude-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).
# 1KSMB39A
**Littelfuse** · Electrostatic And Surge Protection (TVS/ESD) · DO-214AA
1KSMB39A from Littelfuse, in a DO-214AA. 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 terminal of the unidirectional TVS diode, marked by the color band on the DO-214AA (SMB J-Bend) body; 1KSMB39A has VR 33.3V and VBR 37.1-41.0V at 1mA. |
| 2 | Anode | passive | Anode terminal of the unidirectional TVS diode, opposite the cathode band; 1KSMB39A has maximum clamping voltage 53.9V at 18.6A Ipp. |
## Key specifications
| Parameter | Value |
|---|---|
| Manufacturer | Littelfuse |
| Package | DO-214AA |
| Category | TVS/Fuse/Board Level 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 |
|---|---|---|---|---|---|---|---|
| Breakdown Voltage | VBR | 37.1 | | 41 | V | @ IT = 1 mA | 2 |
| Reverse Stand-off Voltage | VR | | 33.3 | | V | | 2 |
| Test Current | IT | | 1 | | mA | | 2 |
| Maximum Clamping Voltage | VC | | | 53.9 | V | @ Ipp = 18.6 A | 2 |
| Maximum Peak Pulse Current | Ipp | | | 18.6 | A | | 2 |
| Maximum Reverse Leakage | IR | | | 1 | µA | @ VR | 2 |
| Maximum Instantaneous Forward Voltage | VF | | | 3.5 | V | at 50A, unidirectional only | 1 |
| Peak Pulse Power Dissipation | PPPM | | | 1000 | W | TA=25ºC, 10/1000µs waveform | 1 |
| Power Dissipation on Infinite Heat Sink | PD | | | 5 | W | TL=50°C | 1 |
| Peak Forward Surge Current | IFSM | | | 120 | A | 8.3ms single half sine wave, unidirectional only | 1 |
| Operating Temperature Range | TJ | -65 | | 150 | °C | | 1 |
| Storage Temperature Range | TSTG | -65 | | 175 | °C | | 1 |
| Thermal Resistance Junction to Lead | RθJL | | 20 | | °C/W | Typical | 1 |
| Thermal Resistance Junction to Ambient | RθJA | | 100 | | °C/W | Typical | 1 |
| Breakdown Voltage Temperature Coefficient | αT | | 0.1 | | % | typical value | 1 |
## Materials and finish
As the datasheet states them (page.json `metadata.appearance`; the 3D model's colours follow it).
| Part | Material | Colour / plating | Datasheet says | Page |
|---|---|---|---|---|
| contacts | | tin | • Matte tin lead-free Plated • Available in breakdown | 1 |
## CAD (KiCad official)
- Symbol: `1KSMB39A`
- Footprint: `Diode_SMD:D_SMB`
- 3D model: DO-214AA (KiCad packages3D, STEP)
- 3D model files: `1ksmb39a-etched.step` / `1ksmb39a-etched.glb` carry the MPN laser-etched on the die in a toggleable `Adom.LaserEtch` group (Fusion-ready); `1ksmb39a.step` / `1ksmb39a.glb` are the bare package body.
## Provenance
Data extracted from the manufacturer datasheet, not a distributor listing:
- **Datasheet:** [Littelfuse datasheet](docs/1ksmb39a-datasheet.pdf) (6 pp, sha256 `3a84dff49a0cb8e5`, retrieved 2026-10-23, 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/1ksmb39a-datasheet.pdf)