STMicroelectronics STP9NK70ZFP

Overview

STP9NK70ZFP 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), and 7.5 A continuous drain current at T_C = 25 °C. It features 100% avalanche testing, 4.5 V/ns peak diode recovery dv/dt capability, and gate charge minimized to 48–68 nC - optimized for high-voltage switching in offline SMPS and lighting ballasts.

For engineers reviewing the STP9NK70ZFP datasheet, STP9NK70ZFP pinout, STP9NK70ZFP application, or STP9NK70ZFP equivalent, key selection criteria include its TO-220FP package thermal resistance (R_thJC = 3.6 °C/W), 230 mJ single-pulse avalanche energy, and Zener-protected gate enabling robust operation in inductive load switching.

Technical Context

This device implements ST's SuperMESH technology - an evolution of PowerMESH - delivering reduced on-resistance while maintaining high dv/dt immunity (4.5 V/ns) and rugged unclamped inductive switching performance. Its Zener-protected gate structure eliminates external gate protection components in high-noise environments.

The MOSFET operates with a gate threshold voltage of 3.0–4.5 V and exhibits low output capacitance (C_oss = 143 pF typ., C_{oss_eq} = 90 pF) and fast switching (t_d(off) = 45 ns typ.), making it suitable for hard-switched flyback and resonant converters operating up to 100 kHz.

Key Specifications

Pinout & Package

STP9NK70ZFP is housed in a TO-220FP (Type B) package - a full-packaged variant with insulated tab, enabling direct mounting to grounded heat sinks without electrical isolation hardware. The plastic body provides creepage/clearance compliant with 2.5 kV RMS insulation rating.

Key Features

Applications

Equivalent & Alternatives

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

Compared with STP8NK80ZFP and FQP7N80C, STP9NK70ZFP delivers optimal balance of 700 V rating, low R_DS(on), Zener gate protection, and proven avalanche ruggedness - making it preferred for cost-constrained yet reliability-critical offline switching designs.

Availability

STP9NK70ZFP is available at Aetrix Electronics and suitable for LED lighting ballasts, offline flyback SMPS, and PFC pre-regulators requiring stable component supply across multi-year production cycles.

Supply support for STP9NK70ZFP 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 industrial, automotive, and consumer markets.

This device belongs to ST's SuperMESH Power MOSFET product line - engineered specifically for high-efficiency, high-reliability switching in AC/DC conversion, lighting, and motor control applications demanding ruggedness and thermal performance.

FAQ

What is the maximum gate-source voltage rating for STP9NK70ZFP?

The absolute maximum V_GS is ±30 V, enforced by internal Zener diodes. Exceeding this risks permanent gate oxide damage. Gate drive circuits must limit transient overshoot using series resistance or clamping, especially in high-di/dt layouts.

Can STP9NK70ZFP be used in synchronous rectification?

No - it is an N-channel enhancement-mode MOSFET optimized for high-side switching, not low-side synchronous rectification. Its body diode forward voltage (V_SD = 1.6 V) and reverse recovery characteristics (t_rr = 570 ns) are unsuitable for high-frequency SR; dedicated SR controllers and logic-level MOSFETs are required instead.

Is the TO-220FP package electrically insulated?

Yes - the TO-220FP (Type B) package features an insulated metal tab rated for 2.5 kV RMS isolation between all three leads and external heatsink. This eliminates need for insulating pads or sleeves when mounting to grounded thermal planes.

What does "100% avalanche tested" mean for this MOSFET?

Each unit undergoes individual unclamped inductive switching stress test at I_AR = 7.5 A and V_DD = 50 V, verifying minimum 230 mJ single-pulse avalanche energy. This guarantees operational robustness in real-world inductive turn-off events without external snubbers.