STMicroelectronics STI21N65M5

Overview

STI21N65M5 from STMicroelectronics is an N-channel 650 V, 150 mΩ typ. (179 mΩ max.), 17 A Power MOSFET in I²PAK package, based on MDmesh M5 vertical process technology. It delivers high dv/dt capability (15 V/ns), 100% avalanche tested performance, and low gate charge (50 nC), making it suitable for high-efficiency AC-DC power supplies and industrial motor drives.

For engineers reviewing the STI21N65M5 datasheet, STI21N65M5 pinout, STI21N65M5 application, or STI21N65M5 equivalent, key selection criteria include R_DS(on) at 10 V drive, unclamped inductive switching robustness (E_AS = 400 mJ), source-drain diode recovery (Q_rr = 4–5 µC), and thermal resistance (R_thJC = 4.17 °C/W).

Technical Context

This device uses ST's MDmesh M5 silicon architecture to achieve ultra-low R_DS(on) while maintaining 650 V breakdown voltage and high dv/dt immunity. Its optimized cell layout reduces output capacitance (C_oss = 46 pF) and reverse transfer capacitance (C_rss = 3 pF), enabling fast switching with low E_on/E_off energy loss.

The integrated body diode features soft recovery (t_rr = 294–340 ns, Q_rr = 4–5 µC) and rated pulsed current up to 68 A, supporting hard-switched PFC and resonant LLC topologies without external diode snubbing.

Key Specifications

Pinout & Package

I²PAK (TO-220AB variant) package with isolated tab; thermally enhanced plastic housing, 3-pin through-hole outline, 13–14 mm lead length, 4.4–4.6 mm body width.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar high-voltage power switching applications.

Compared with STI21N65M5, STP21N65M5 offers superior thermal conduction but requires more PCB area, while STF21N65M5 matches its thermal resistance in a lower-profile package-making STI21N65M5 optimal for balanced thermal, mechanical, and layout requirements in mid-power industrial converters.

Availability

STI21N65M5 is available at Aetrix Electronics and suitable for industrial motor drives, server power supplies, photovoltaic inverters, and EV onboard chargers requiring stable component supply across multi-year production cycles.

Supply support for STI21N65M5 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.

STI21N65M5 belongs to the MDmesh M5 Power MOSFET product line, engineered specifically for high-efficiency, high-reliability switching in 600–650 V power conversion systems where low R_DS(on), fast switching, and ruggedness are critical.

FAQ

What is the maximum recommended gate-source voltage for STI21N65M5?

The absolute maximum V_GS is ±25 V, but ST recommends limiting continuous gate drive to ±20 V to ensure long-term reliability. Gate oxide integrity is preserved under this condition, and typical gate drivers (e.g., STGAP2S, UCC27531) operate safely within 12–15 V logic-compatible levels. Exceeding ±20 V risks accelerated threshold voltage shift over temperature and lifetime.

Does STI21N65M5 require a gate resistor, and what value is recommended?

Yes - a gate resistor is mandatory to control dV/dt and suppress oscillation. For 100 kHz operation with 12 V drive, ST's datasheet specifies 4.7 Ω (R_G) in test conditions yielding t_d(off) = 37 ns and t_f(i) = 12 ns. Lower values (2.2–3.3 Ω) improve switching speed but increase EMI risk; higher values (10–22 Ω) reduce ringing at the cost of increased switching loss.

Can STI21N65M5 replace older STP22N60M2 devices in existing designs?

Yes - STI21N65M5 offers lower R_DS(on) (150 mΩ vs. 220 mΩ), higher V_DSS (650 V vs. 600 V), and improved dv/dt immunity (15 V/ns vs. 10 V/ns). Pinout is identical in I²PAK, and gate threshold (3–5 V) matches. However, Q_g is higher (50 nC vs. 38 nC), so gate driver capability must be verified before drop-in replacement.

Is the source-drain diode suitable for freewheeling in synchronous rectification?

No - while rated for 17 A continuous and 68 A pulsed, the body diode has relatively high V_SD (1.5 V) and moderate Q_rr (4–5 µC), making it inefficient for high-frequency synchronous rectification. It is intended for clamping, snubbing, or low-duty-cycle freewheeling. For synchronous rectification, external Schottky or SiC diodes are strongly recommended.