STMicroelectronics STripFET™ II STP85NF55, N-Channel MOSFET, 55 V drain-to-source, 80 A continuous drain, 8 mOhm Rds(on) at 10 V, 150 nC gate charge, TO-220-3 through-hole package, -55°C to 175°C junction temperature.
| Parameter | Value |
|---|---|
| Series | STripFET™ II |
| FET type | N-Channel |
| Mounting | Through Hole |
| Drain to source voltage | 55 V |
| Drive voltage (Max rds on, min rds on) | 10V |
| Current - continuous drain (Id) @ 25°C | 80A (Tc) |
| Power dissipation | 300W (Tc) |
| Operating temperature | -55°C~175°C(TJ) |
| Package | Tube |
| Vgs | ±20V |
| Technology | MOSFET (Metal Oxide) |
| Case | TO-220-3 |
| Vgs(th) (Max) @ id | 4V @ 250µA |
| Rds on (Max) @ id, vgs | 8mOhm @ 40A, 10V |
| Gate charge (Qg) (Max) @ vgs | 150 nC @ 10 V |
| Input capacitance (Ciss) (Max) @ vds | 3700 pF @ 25 V |
The 55 V drain-to-source rating sets the maximum bus voltage this FET can block; in a 48 V nominal system with transients, you need derating headroom. Gate charge of 150 nC at 10 V tells you the driver must supply that charge per switching cycle — a 1 A gate driver charges the gate in about 150 ns, but the 3700 pF input capacitance also affects switching speed and drive losses.
For new designs, a pin-compatible replacement should be identified.
The STP85NF55 is obsolete and no longer in production, but it can be sourced through independent distribution. Submit an RFQ for current availability and pricing — the part is quoted to order, not stocked on the shelf.
For a pin-compatible alternative, look for other N-channel MOSFETs in the TO-220-3 package with similar 55 V drain-source and 80 A current ratings from ST's STripFET family or competitors — but verify the gate drive and Rds(on) match your design.