DMN2009LSS

The DMN2009LSS from Diodes Incorporated is a single N-channel enhancement-mode power MOSFET in the industry-standard SO-8 package. With 20 V drain-source rating and 12 A continuous current capability, it targets high-current, low-voltage power management applications including DC-DC converters, load switches, and motor drives.

The ultra-low 8 mΩ maximum RDS(on) at VGS = 10 V (9 mΩ at 4.5 V, 12 mΩ at 2.5 V) is achieved through Diodes’ trench MOSFET technology. At 10 A load, the conduction loss is only 0.8 W (8 mΩ × 10²A), well within the 2 W package rating with adequate PCB copper area.

The 0.5 V minimum threshold voltage ensures the device can be driven from logic-level signals, while the 1.2 V maximum threshold guarantees full enhancement at 2.5 V gate drive. This wide threshold range means the device works well at both 2.5 V and 5 V gate drive, though RDS(on) is significantly lower at 4.5 V and above.

The SO-8 package provides a good balance between current handling and PCB area. The 2 W power dissipation rating assumes adequate thermal design — typically a 1 square-inch copper pour on the drain pins with thermal vias to internal ground planes.

The DMN2009LSS is part of Diodes’ DMN20xx family of 20 V N-channel MOSFETs. Related devices include the DMN2009USS (same die in a different SO-8 variant) and DMN2016UTS (dual N-channel version). The -13 suffix variant denotes tape-and-reel packaging.

For applications requiring automotive qualification, Diodes offers AEC-Q101 qualified variants (identified by ‘Q’ suffix).

**N-Channel Trench MOSFET:** The DMN2009LSS uses trench gate technology where vertical trenches are etched into the silicon and the gate electrode is formed inside these trenches. This creates a very large channel width per unit die area, resulting in the ultra-low 8 mΩ RDS(on). The vertical current flow from source (top) to drain (bottom) through the trench structure provides efficient current handling.

**Gate Drive Considerations:** The 0.5-1.2 V threshold range means the device can be driven from logic levels. At VGS = 4.5 V, RDS(on) is 9 mΩ maximum — only slightly higher than at 10 V. This logic-level optimization makes the device suitable for direct MCU GPIO drive in load-switch applications. At VGS = 2.5 V, RDS(on) increases to 12 mΩ, still very low for most applications.

**SO-8 Package Thermal Design:** The SO-8 package dissipates heat primarily through the drain leads (pins 5-8 for single MOSFET configuration) into the PCB copper. The 2 W rating at 25°C ambient requires approximately 1 square inch of 1 oz copper on the drain pads. For higher dissipation, thermal vias connecting to internal copper planes improve thermal performance.

**Body Diode:** The inherent body diode from source to drain has a forward voltage of approximately 0.9 V at 1 A. In synchronous rectifier applications, this diode conducts during the dead time between high-side and low-side switch transitions.