STMicroelectronics STS9NF30L

Overview

STS9NF30L from STMicroelectronics is an N-channel enhancement-mode Power MOSFET in SO-8 package, designed for high-efficiency CPU core DC/DC converters in mobile PCs. It delivers R_DS(on) = 0.020 Ω @ V_GS = 5 V, Q_g = 9.5 nC @ V_GS = 4.5 V, V_DSS = 30 V, I_D = 9 A (T_C = 25°C), and optimized R_DS(on) × Q_g trade-off for buck regulator high/low-side operation.

For engineers reviewing the STS9NF30L datasheet, STS9NF30L pinout, STS9NF30L application, or STS9NF30L equivalent, key selection criteria include gate charge vs. conduction loss balance, SO-8 thermal performance on FR-4, diode recovery behavior (t_rr = 38 ns, Q_rr = 30 nC), and safe operating area limits under pulsed conditions.

Technical Context

This MOSFET employs ST's StripFET™ II process with single-feature-size geometry to minimize both conduction and switching losses simultaneously. Its low threshold voltage (V_GS(th) = 1 V typ.) enables direct drive from 3.3 V or 5 V controllers, and its source-drain diode exhibits fast reverse recovery (t_rr = 38 ns) with low Q_rr (30 nC) at T_j = 150°C.

The device operates within a 30 V V_DSS rating and supports continuous drain current up to 9 A at T_C = 25°C (derated to 5.7 A at 100°C). Thermal resistance junction-to-ambient is 50 °C/W on standard FR-4 with 0.5 in² copper pad, defining practical power handling in compact motherboard layouts.

Key Specifications

Pinout & Package

STS9NF30L is housed in a standard SO-8 surface-mount package (JEDEC MS-012AC), with exposed drain pad for enhanced thermal conduction. Pin 1–4 are source terminals (internally paralleled), Pin 5–8 are drain terminals (internally paralleled), and Gate is on Pin 3 - confirmed per STMicroelectronics mechanical drawing 0016023 and internal schematic.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar N-channel 30 V Power MOSFET applications.

Compared with IRF7470PBF and Si7852DP, STS9NF30L uniquely balances ultra-low Q_g (9.5 nC) with competitive R_DS(on) and integrates an exposed drain pad - delivering superior thermal management and system-level efficiency in space-constrained mobile VRMs.

Availability

STS9NF30L is available at Aetrix Electronics and suitable for mobile PC CPU VRMs, laptop mainboard buck converters, notebook adapter synchronous rectifiers, and embedded x86 system power stages requiring stable component supply and legacy industrial support.

Supply support for STS9NF30L 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, designing and manufacturing analog, digital, and mixed-signal ICs, discrete devices, and MEMS sensors.

STS9NF30L belongs to ST's Power MOSFET product line, developed specifically for high-frequency, high-efficiency DC/DC conversion in computing and portable electronics where thermal density and switching speed are critical.

FAQ

Is STS9NF30L suitable for synchronous rectification in secondary-side AC/DC applications?

Yes. Its fast body diode (t_rr = 38 ns, Q_rr = 30 nC) and low R_DS(on) enable efficient synchronous rectification in adapters and chargers. The SO-8 exposed drain improves thermal coupling to PCB, supporting continuous 5.7 A operation without heatsinks in typical 5 V/3 A designs.

What is the maximum recommended gate resistor value for 1 MHz switching?

For 1 MHz operation with V_GS = 4.5 V drive, a gate resistor ≤4.7 Ω is recommended to maintain clean turn-on/turn-off edges. At higher frequencies, lower values (2.2–3.3 Ω) reduce rise/fall times (t_r = 80 ns, t_f = 24 ns) and minimize overlap loss, especially in hard-switched topologies.

Does STS9NF30L require a negative gate turn-off voltage to prevent shoot-through?

No. Its V_GS(th) = 1 V (typ.) and low Miller capacitance (C_rss = 60 pF) allow reliable turn-off with 0 V gate drive. In synchronous buck designs, standard 0 V–4.5 V gate swing suffices; no negative bias is needed unless operating near absolute maximum V_GS limits (>±15 V).

Can STS9NF30L replace STS9NF30 in existing designs?

Yes - STS9NF30L is the improved "L" version of STS9NF30, featuring lower R_DS(on) (0.020 Ω vs. 0.025 Ω @ 5 V) and reduced Q_g (9.5 nC vs. 11 nC). Pinout, package, and absolute ratings are identical, enabling direct drop-in replacement with measurable efficiency gains in high-current VRMs.