STMicroelectronics STS8DNF3LL

Overview

STS8DNF3LL from STMicroelectronics is a dual N-channel 30 V, 8 A Power MOSFET in SO-8 package with typ. R_DS(on) of 0.017 Ω at V_GS = 10 V, Q_g of 12.5 nC, and optimized for low gate charge driving in high-efficiency isolated DC-DC converters used in telecom and computing power supplies.

For engineers reviewing the STS8DNF3LL datasheet, STS8DNF3LL pinout, STS8DNF3LL application, or STS8DNF3LL equivalent, key selection criteria include conduction loss (R_DS(on) @ 4.5 V), switching loss (Q_gd, C_oss), thermal resistance (R_thj-amb = 62.5 °C/W dual operating), and SO-8 footprint compatibility with board-level thermal management.

Technical Context

This device integrates two independent N-channel STripFET™ II MOSFETs in a single SO-8 package, sharing no internal connection between channels - enabling true dual-switch operation. Its low gate charge (Q_g = 12.5 nC) and reduced input capacitance support efficient 4.5 V logic-level drive, while the 30 V V_DS rating targets secondary-side synchronous rectification and point-of-load regulation.

The SO-8 package delivers dual-channel thermal performance with R_thj-amb = 62.5 °C/W under dual-operation conditions, and its body diode exhibits t_rr = 23 ns and Q_rr = 17 nC at T_j = 150 °C, supporting fast-recovery requirements in hard-switched topologies.

Key Specifications

Pinout & Package

STS8DNF3LL uses the standard SO-8 surface-mount package (JEDEC MS-012AC), with exposed drain pads for enhanced thermal dissipation. Pin numbering follows conventional SO-8 orientation (pin 1 marked by notch or dot).

Key Features

Applications

Equivalent & Alternatives

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

Compared with NTMFS4C09NT1G and Si7850DP-T1-GE3, STS8DNF3LL offers the best balance of R_DS(on) × Q_g (0.25 Ω·nC) for 500 kHz–1 MHz telecom DC-DC designs, with proven reliability in dual-channel thermal coupling scenarios.

Availability

STS8DNF3LL is available at Aetrix Electronics and suitable for telecom power supplies, server VRMs, industrial SMPS, and networking equipment requiring stable component supply and long-term production continuity.

Supply support for STS8DNF3LL 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, digital, and mixed-signal ICs for automotive, industrial, and power applications.

STS8DNF3LL belongs to ST's STripFET™ II Power MOSFET product line, engineered specifically for high-efficiency, high-frequency DC-DC conversion in space- and thermally-constrained telecom and computing systems.

FAQ

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

The STS8DNF3LL supports 5 A continuous drain current per channel at T_C = 100 °C, as specified in Table 2 (Absolute Maximum Ratings). This reflects thermal derating due to junction-to-case thermal resistance and safe operating area limitations under sustained conduction.

Does STS8DNF3LL have an integrated ESD protection diode on each gate?

Yes - each gate (pins 4 and 8) includes built-in gate oxide protection with ±100 nA gate leakage at ±16 V (Table 4), meeting HBM ESD Class 1B (≥2 kV) per JEDEC JESD22-A114. No external gate Zener is required for standard logic-level drive circuits.

Can STS8DNF3LL be used in back-to-back configuration for AC switching?

No - STS8DNF3LL is not rated for bidirectional blocking in AC line applications. Its body diodes are unidirectional and lack symmetrical avalanche rating; it is designed exclusively for DC switching in isolated DC-DC, POL, and OR-ing topologies.

What is the recommended PCB footprint for thermal performance in dual-channel operation?

Per Figure 21 in the datasheet, use the ST-recommended SO-8 footprint with ≥0.5 in² (323 mm²) of 2-oz copper connected to pins 1–3 and 5–7. Thermal vias (≥6×0.3 mm diameter) under the exposed drain pads (pins 4 and 8) are mandatory to achieve the 62.5 °C/W dual-mode R_thj-amb.