STMicroelectronics STP9NK90Z

Overview

STP9NK90Z from STMicroelectronics is a Zener-protected N-channel SuperMESH Power MOSFET rated for 900 V drain-source voltage, 1.3 Ω max R_DS(on) at V_GS = 10 V and I_D = 3.6 A, with 8 A continuous drain current at T_C = 25 °C. It delivers high dv/dt capability (4.5 V/ns), 100% avalanche tested performance, and low gate charge (72 nC), enabling robust operation in high-voltage flyback and resonant converters.

For engineers reviewing the STP9NK90Z datasheet, STP9NK90Z pinout, STP9NK90Z application, or STP9NK90Z equivalent, this device is selected for high-reliability offline SMPS, industrial AC-DC power supplies, and solid-state relay drivers where high-voltage blocking, avalanche ruggedness, and fast switching are critical.

Technical Context

This MOSFET employs ST's SuperMESH process-a refined iteration of PowerMESH-optimized to reduce on-resistance while preserving high-voltage integrity and dynamic robustness. Its Zener-protected gate structure ensures ESD immunity up to 4 kV (HBM) and stable threshold voltage (3.0–4.5 V) across temperature.

The device exhibits low intrinsic capacitance (C_iss = 2115 pF, C_oss = 190 pF, C_rss = 40 pF) and fast switching (t_d(on) = 22 ns, t_f = 28 ns), supporting high-frequency operation in hard-switched topologies without compromising SOA or thermal stability.

Key Specifications

Pinout & Package

STP9NK90Z is supplied in TO-220 package (Type A), with isolated tab (drain-connected). The case is electrically insulated from heatsink via mounting hardware; no external isolation washer required when using recommended torque (0.5–0.7 N·m).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar high-voltage N-channel MOSFET applications.

Compared with STW9NK90Z, STP9NK90Z trades thermal performance for compact footprint and lower assembly cost; versus FQP9N90C, it provides guaranteed avalanche ruggedness and gate protection critical for industrial field reliability-making it preferred for certified power systems.

Availability

STP9NK90Z is available at Aetrix Electronics and suitable for industrial AC-DC power supplies, high-voltage flyback converters, and solid-state relay drivers requiring stable component supply and long-term manufacturing continuity.

Supply support for STP9NK90Z includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

STMicroelectronics is a global semiconductor leader headquartered in Geneva, Switzerland, specializing in power management, microcontrollers, and analog/mixed-signal ICs for industrial, automotive, and consumer markets.

STP9NK90Z belongs to the SuperMESH Power MOSFET product line, engineered specifically for high-efficiency, high-reliability offline switch-mode power conversion where voltage endurance, avalanche safety, and thermal robustness are mandatory.

FAQ

Is STP9NK90Z pin-compatible with other 3-pin TO-220 N-channel MOSFETs?

Yes-STP9NK90Z uses standard TO-220 Type A pinout (G-D-S, left-to-right with tab facing down), matching industry conventions. However, its 900 V rating and 1.3 Ω R_DS(on) differ significantly from lower-voltage parts; direct substitution requires verification of SOA, gate drive strength, and thermal margin.

What is the maximum recommended gate resistor value for reliable switching?

For 100 kHz operation with 1 A peak gate driver, R_G ≤ 10 Ω maintains t_f < 30 ns and minimizes Miller-induced oscillation. At 4.7 Ω (per datasheet test condition), turn-off delay is 55 ns-critical for ZVS timing control in resonant topologies.

Does STP9NK90Z require external gate protection in standard applications?

No-its integrated Zener clamp protects gate oxide against ±30 V transients and 4 kV HBM ESD, eliminating need for external TVS diodes in properly laid-out PCBs. External RC snubbers remain advisable only for extreme dv/dt environments (>6 V/ns) or poorly damped layouts.

Can STP9NK90Z replace STB9NK90Z in D²PAK-based designs?

No-STB9NK90Z (D²PAK) and STP9NK90Z (TO-220) share identical die but differ in thermal resistance (R_thJC = 0.78 °C/W vs 3.1 °C/W) and footprint. Substitution requires mechanical redesign, thermal revalidation, and gate loop inductance reassessment due to different leadframe geometry.