STMicroelectronics STL9N3LLH5

Overview

STL9N3LLH5 from STMicroelectronics is an N-channel 30 V Power MOSFET in PowerFLAT™ (3.3×3.3) package, optimized for high-efficiency switching with 15 mΩ typ. R_DS(on), 9 A continuous drain current at T_C = 25 °C, and 5 nC total gate charge. It delivers low conduction and switching losses in compact DC-DC converters and motor drive half-bridges.

For engineers reviewing the STL9N3LLH5 datasheet, STL9N3LLH5 pinout, STL9N3LLH5 application, or STL9N3LLH5 equivalent, key selection criteria include its 30 V V_DS, 15 mΩ R_DS(on) at 10 V_GS, 5 nC Q_g, thermal resistance of 2.5 °C/W (j-case), and avalanche ruggedness (E_AS = 150 mJ).

Technical Context

This device implements ST's STripFET™ V process to minimize R_DS(on) × Q_g figure-of-merit, enabling high-frequency operation with reduced gate drive power loss. Its 2.5 °C/W junction-to-case thermal resistance supports high-power density layouts when mounted on copper-poured PCBs.

The MOSFET features a robust body diode with 21 ns reverse recovery time and 10 nC Q_rr at 150 °C, making it suitable for synchronous rectification and inductive load switching where diode performance impacts efficiency and EMI.

Key Specifications

Pinout & Package

STL9N3LLH5 uses the PowerFLAT™ (3.3 × 3.3 mm) surface-mount package with exposed drain pad for thermal and electrical connection. The package has 5 terminals: 3 drain pins (D), 1 source (S), and 1 gate (G), arranged in a single-row configuration optimized for automated assembly and PCB thermal relief.

Key Features

Applications

Equivalent & Alternatives

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

Compared with BSC014N03LS and NTMFS4C02NT1G, STL9N3LLH5 offers the best balance of R_DS(on) and Q_g for 30 V switching above 500 kHz, with proven avalanche robustness critical for motor and inductive loads.

Availability

STL9N3LLH5 is available at Aetrix Electronics and suitable for DC-DC converters, BLDC motor drives, USB-C power delivery switches, and LED current switches requiring stable component supply and long-term production continuity.

Supply support for STL9N3LLH5 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 analog, microcontroller, power, and sensor solutions for industrial, automotive, and consumer markets.

This part belongs to ST's STripFET™ V Power MOSFET product line, engineered specifically for high-efficiency, high-frequency switching in space-constrained power stages such as point-of-load converters and motor inverters.

FAQ

What is the maximum continuous drain current at 100 °C case temperature?

The STL9N3LLH5 supports 6 A continuous drain current at T_C = 100 °C, per Table 2 in the datasheet. This derating reflects thermal limits of the PowerFLAT™ package and requires adequate PCB copper area to maintain junction temperature below 150 °C under sustained load.

Is the body diode suitable for synchronous rectification?

Yes - the intrinsic body diode has t_rr = 21 ns and Q_rr = 10 nC at 150 °C, enabling efficient synchronous rectification in buck converters up to 1 MHz. Its soft recovery characteristic reduces EMI compared to standard silicon diodes.

Does this MOSFET require a gate resistor for stability?

A gate resistor (typically 4.7 Ω) is recommended to dampen gate ringing and prevent spurious turn-on due to high dv/dt. The low 5 nC Q_g makes it susceptible to parasitic oscillation without proper gate network design, especially in high-speed switching layouts.

What is the safe operating area (SOA) limitation at DC operation?

At DC, the SOA is limited by R_DS(on) and thermal resistance: maximum power dissipation is 2 W on FR-4 (R_thj-pcb = 63.5 °C/W) and 50 W with heatsink (R_thj-case = 2.5 °C/W). Derating is 0.4 W/°C above 25 °C case temperature.