# TSF840MD

**Truesemi** · MOSFETs · TO-220F-3

TSF840MD from Truesemi, in a TO-220F-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 | G | input | Gate; controls the MOSFET with a gate-source voltage limit of ±30 V and a threshold of 2.0 to 4.0 V. |
| 2 | D | passive | Drain; 500 V maximum drain-source voltage and 8.0 A continuous drain current at TC = 25℃ (limited by junction temperature). |
| 3 | S | passive | Source; the body diode conducts from source to drain with a continuous forward current of 8.0 A. |

## Key specifications

| Parameter | Value |
|---|---|
| Manufacturer | Truesemi |
| Package | TO-220F-3 |
| Category | Transistors/Thyristors |
| 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 |
|---|---|---|---|---|---|---|---|
| Drain-Source Voltage | VDSS |  |  | 500 | V |  | 1 |
| Gate-Source Voltage | VGS | -30 |  | 30 | V |  | 1 |
| Drain Current | ID |  |  | 8 | A | TC = 25℃; drain current limited by maximum junction temperature | 1 |
| Drain Current | ID |  |  | 5 | A | TC = 100℃ | 1 |
| Pulsed Drain Current | IDM |  |  | 32 | A | Note 1 | 1 |
| Single Pulsed Avalanche Energy | EAS |  |  | 360 | mJ | Note 2 | 1 |
| Repetitive Avalanche Energy | EAR |  |  | 13.9 | mJ | Note 1 | 1 |
| Peak Diode Recovery dv/dt | dv/dt |  |  | 4.5 | V/ns | Note 3 | 1 |
| Power Dissipation | PD |  |  | 45.5 | W | TC = 25℃ | 1 |
| Operating and Storage Temperature Range | TJ, TSTG | -55 |  | 150 | ℃ |  | 1 |
| Maximum lead temperature for soldering purposes | TL |  |  | 300 | ℃ | 1/8 in from case for 5 seconds | 1 |
| Thermal Resistance, Junction-to-Case | RθJC |  |  | 2.75 | ℃/W |  | 1 |
| Thermal Resistance, Junction-to-Ambient | RθJA |  |  | 62.5 | ℃/W |  | 1 |
| Continuous Source-Drain Diode Forward Current | IS |  |  | 8 | A |  | 2 |
| Pulsed Source-Drain Diode Forward Current | ISM |  |  | 36 | A |  | 2 |
| Source-Drain Diode Forward Voltage | VSD |  |  | 1.4 | V | IS = 9.0 A, VGS = 0 V | 2 |
| Drain-Source Breakdown Voltage | BVDSS | 500 |  |  | V | VGS = 0 V, ID = 250 uA | 2 |
| Zero Gate Voltage Drain Current | IDSS |  |  | 1 | uA | VDS = 500 V, VGS = 0 V | 2 |
| Zero Gate Voltage Drain Current | IDSS |  |  | 10 | uA | VDS = 400 V, TJ = 125℃ | 2 |
| Gate-Body Leakage Current, Forward | IGSSF |  |  | 100 | nA | VGS = 30 V, VDS = 0 V | 2 |
| Gate-Body Leakage Current, Reverse | IGSSR |  |  | -100 | nA | VGS = -30 V, VDS = 0 V | 2 |
| Gate Threshold Voltage | VGS | 2 |  | 4 | V | VDS = VGS, ID = 250 uA | 2 |
| Static Drain-Source On-Resistance | RDS(ON) |  | 0.88 | 0.95 | Ω | VGS = 10 V, ID = 4.5 A | 2 |

## CAD (KiCad official)

- Symbol: `TSF840MD`
- Footprint: `Package_TO_SOT_THT:TO-220F-3_Vertical`
- 3D model: TO-220F-3 (KiCad packages3D, STEP)

## Provenance

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

- **Datasheet:** [Truesemi datasheet](https://jlcpcb.com/api/file/downloadByFileSystemAccessId/8588904306284511232) (6 pp, sha256 `ab8ad807527b0b4b`, retrieved 2026-10-15, tier: lcsc)
- **Extractor:** parts-factory `2.0.0` / `extract_pins 0.3`, primary `claude-sonnet-5-5` (text+vision), consensus `claude-opus-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/tsf840md-datasheet.pdf)