STMicroelectronics STB9NK70Z-1

Overview

STB9NK70Z-1 from STMicroelectronics is a Zener-protected N-channel SuperMESH Power MOSFET rated for 700 V drain-source voltage, 1.2 Ω max R_DS(on) at 10 V_GS, and 7.5 A continuous drain current at T_C = 25 °C. It delivers high dv/dt capability (4.5 V/ns), 100% avalanche tested robustness, and gate charge minimized to 48–68 nC - deployed in high-reliability offline SMPS and AC-DC adapters.

For engineers reviewing the STB9NK70Z-1 datasheet, STB9NK70Z-1 pinout, STB9NK70Z-1 application, or STB9NK70Z-1 equivalent, key selection criteria include verified avalanche energy (230 mJ), insulated package rating (2.5 kV RMS), thermal resistance (3.6 °C/W junction-to-case), and TO-220FP pin-compatible layout with isolated tab.

Technical Context

This device implements ST's SuperMESH process - an evolution of PowerMESH - optimizing cell pitch and drift region doping to reduce on-resistance while preserving ruggedness. Its Zener-protected gate structure enables reliable operation under transient overvoltage conditions without external clamping.

The TO-220FP package features electrically isolated tab (2.5 kV RMS insulation), enabling direct heatsink mounting without insulating hardware. Dynamic parameters - including C_iss = 1370 pF, Q_gd = 27 nC, and t_r = 17 ns - are tuned for fast switching in hard-switched flyback and resonant LLC topologies.

Key Specifications

Pinout & Package

STB9NK70Z-1 is housed in a TO-220FP (Type B) package with electrically isolated metal tab rated for 2.5 kV RMS insulation. The plastic body provides creepage/clearance compliance for reinforced isolation in safety-critical power supplies.

Key Features

Applications

Equivalent & Alternatives

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

Compared with STB9NK70Z-1, STP9NK70ZFP offers identical performance with validated documentation and lifecycle support, while FQP7N70 trades ruggedness and isolation for lower cost - making STP9NK70ZFP the recommended drop-in replacement for new designs.

Availability

STB9NK70Z-1 is available at Aetrix Electronics and suitable for AC-DC adapters, industrial flyback SMPS, and LED driver bulk switches requiring stable component supply, consistent parametric performance, and long-term manufacturing continuity.

Supply support for STB9NK70Z-1 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, designing and manufacturing microcontrollers, power devices, sensors, and analog ICs for automotive, industrial, and consumer markets.

STB9NK70Z-1 belongs to ST's SuperMESH Power MOSFET product line, engineered specifically for high-efficiency, high-reliability offline switching power supplies where avalanche robustness, dv/dt immunity, and gate protection are mandatory.

FAQ

Is STB9NK70Z-1 pin-compatible with STP9NK70ZFP?

Yes - both use identical TO-220FP (Type B) packaging with G-D-S pinout (Pin 1 = Gate, Pin 2 = Drain, Pin 3 = Source) and electrically isolated tab. Mechanical dimensions, thermal pad layout, and mounting hole positions match exactly per ST's DS2726 Rev 3 package drawings.

What is the maximum safe operating temperature for STB9NK70Z-1?

The absolute maximum junction temperature is 150 °C, with continuous operation limited to 125 °C for reliability. At T_C = 100 °C, the drain current derates to 4.7 A. Thermal design must account for R_thJC = 3.6 °C/W and ensure heatsink interface resistance keeps T_J within this limit under worst-case load and ambient conditions.

Does STB9NK70Z-1 require external gate protection?

No - it integrates a monolithic Zener diode between gate and source, clamping V_GS to ±30 V. This eliminates the need for external TVS diodes or resistors in standard gate drive circuits, though a series gate resistor (typically 10–47 Ω) remains necessary to control dV/dt and suppress ringing.

Can STB9NK70Z-1 replace STW9NK70Z in TO-247 packages?

No - STW9NK70Z uses TO-247 package with different pinout (G-S-D), higher power dissipation (PTOT = 190 W), and lower R_thJC (0.55 °C/W). STB9NK70Z-1's TO-220FP limits PTOT to 35 W and cannot handle equivalent current/power without thermal violation; mechanical and electrical interfaces are incompatible.