Aug 26, 2015 | By:

Fairchild’s Dual Cool™ 88 package gives engineers a first of its kind alternative to the D2PAK and TO-220 packages they’ve been using to mount discreet, 10mm X 15mm, semiconductors onto PCBs for the last 30 years, not quite the stone age in historical terms, but given the advancement in electronics since the 1980’s, it may as well be. With their extended leads for high heat dissipation, D2-PAK, TO-263, and TO-220 packages have been the most efficient/cost-effective way to implement discrete MOSFETs that require high heat dissipation. However, demand for higher power density is making the tried and true D2PAK/TO-220 packages insufficient as far as thermal dissipation is concerned, while requirements for smaller form factors further reduce their appeal.

Instead of requiring leads extending from the package molding, Fairchild’s Dual Cool technology dissipates heat from both the bottom pad AND the copper slug exposed on the top of the package. This means more efficient heat dissipation across a wider area, making it easier for manufacturers to increase the efficiency of applications such as DC motors, while also reducing costs, when they use higher power density MOSFETs.

Dual Cool 88 blog

The construction of the Dual Cool packaging also makes them smaller and lighter than D2-PAK and similar surface mount packages. Because thermal budgets are finite in any given design, increasing thermal efficiency can have a huge impact on the final product in terms of cost and size. In fact, Dual Cool 88 devices can easily accommodate the die size of the D2PAK with 53% less area while being 78% thinner.

The Dual Cool’s copper source clip technology, rather than traditional source bond wires, reduces inductive switching spikes and provides higher pulse current capabilities. This is because the copper source clip makes the connection from the top of the die to the external pins, while the copper heat slug that it’s soldered to creates a highly efficient thermal conduction path outside the package. You can learn more in this Dual Cool technology video featuring our Dual Cool 33 and Dual Cool 56 packages.

Dual Cool thermal capabilities can be further enhanced by allowing a heat sink on top of the package, which would not be viable for a D2PAK or TO-220, due to its thick mold compound that restricts heat flow from the top. Also, similar to the Power 88 that we wrote about in an earlier blog, the Dual Cool 88 also comes with the highest Moisture Sensitivity Level of MSL1.

The new Dual Cool 88 family includes N Channel MOSFETS between 30V and 150V, making them ideal for products, such as drones, that require small size along with high power density. Other applications would include AC-DC and DC-DC power supplies for solar, hot swapping, or power tools and other brushed or brushless DC motor applications.

So leave your D2PAK and TO-220 packages in the past and bring your design into the 21st century by taking advantage of Fairchild’s Dual Cool 88 package technology advancements. Start by learning more about Dual Cool technology at There you’ll find links to application notes, data sheets and just about everything you’ll need to get going.

This post is also available in: Chinese (Simplified)