STF21N90K5

STF21N90K5 is STMicroelectronics’ high-voltage N-channel power MOSFET. Designed for switching power electronics, it uses trench MOSFET technology to deliver a 900 V drain‑to‑source rating with a current rating in the tens of amperes range (datasheet specifies the exact Id) and low on-resistance for efficient operation. It’s suited for switch‑mode power supplies, PFC stages, inverters, and motor drives, and is available in common power packages such as TO‑220, D²PAK, and DPAK. Gate drive is typically around 10–12 V, and proper gate drive circuitry plus adequate heat sinking are required for reliable operation. For precise specifications—Rds(on), Id, Safe Operating Area (SOA), switching characteristics, and pinout—consult the official datasheet. The STF family emphasizes high‑voltage, higher‑power switching with rugged avalanche capability.

STF21N90K5 is a 900 V, ~21 A N-channel MOSFET (ST SuperFET). Direct equivalents depend on package and exact electrical specs. In general, 900 V N‑channel MOSFETs from Vishay, Infineon, and ON Semi with similar Id and Rds(on) can substitute. To give precise cross‑refs, please provide the package (TO‑220, D²PAK, etc.), max Rds(on), Id, and gate charge, or share the ST cross‑reference table you’re using.

STF21N90K5 is a high-voltage N-channel MOSFET. Key features:
- 900 V blocking voltage
- 21 A continuous drain current
- N-channel enhancement mode with trench technology for better performance
- Fast switching with low gate-drive energy
- Avalanche rugged and inductive-load protection
- Good dv/dt and di/dt immunity
- Suitable for offline switch-mode power supplies, inverters, motor drives, etc.
- Wide operating temperature range (high-temp capability)
- RoHS compliant (lead-free)
Notes: exact Rds(on) and package options are in the datasheet; this summary focuses on typical power and switching features.

- Pin count: 3 pins (plus an exposed drain tab)
- Pinout (TO‑220 style, facing you): Pin 1 = Gate, Pin 2 = Drain, Pin 3 = Source; the tab is Drain
- Function: N‑channel enhancement‑mode power MOSFET used as a high‑voltage switch/converter device.

Manufacturer: STMicroelectronics (ST).
What kind of company: A multinational electronics and semiconductor company, based in Europe, designing and manufacturing integrated circuits, power MOSFETs and other discrete devices, sensors, microcontrollers (e.g., STM32), and related semiconductor products.

STF21N90K5 is a high‑voltage N‑channel power MOSFET. Typical applications include:
- Offline switch‑mode power supplies (flyback/forward, PFC)
- Solar inverters and grid‑tied power electronics
- Motor drives (BLDC, PMSM, induction) and other high‑voltage switching stages
- Uninterruptible power supplies (UPS) and energy‑storage converters
- General high‑voltage DC‑DC/DC‑AC power conversion in industrial equipment and appliances

Typically D²PAK (TO-263) surface-mount package. Verify with the ST datasheet for the exact packaging.