New Industry Products

Fairchild Intros New Bottomless SO-8 MOSFET Family

August 06, 2002 by Jeff Shepard

Fairchild Semiconductor International (San Jose, CA) introduced a new family of 18 n-channel MOSFETs housed in the industry’s first bottomless package that combines the thermal performance of the much larger TO-263 (D2-PAK) with very low RDS(on) in a standard SO-8 package outline.

The 18 new products include the 150V FDS2070N3 and FDS2070N7 and the 200V FDS2170N3 and FDS2170N7 products for 48V telecom dc/dc applications, which feature high efficiency, low RDS(on), low gate charge, and synchronous or conventional switching PWM controllers. The three-source FDS4070N3, FDS4072N3 and FDS4080N3, and the seven-source FDS4070N7, FDS4072N7 and FDS4080N7 40V products are capable of achieving RDS(on) as low as 7mW and are designed for use in the primary-side of low-input-voltage, single transistor, forward dc/dc converters; transistor forward converters; and half-bridge converters.

Also available now are the three-source pin-out FDS6064N3 and FDS6162N3, and the seven-source pin-out FDS6064N7 and FDS6162N7 20V products featuring on-resistance capabilities as low as 3.5mW. The three-source pin-out FDS7066N3 and FDS7064N, and the seven-source FDS7066N7 and FDS7064N7 30V MOSFETs feature on-resistances as low as 5.5mW. Both the 20V and 30V bottomless SO-8 products are targeted at low-side switch applications in notebook; desktop computer; and computing and synchronous rectifier, isolated, dc/dc converter applications.

The Fairchild bottomless package is constructed using the company's solder-bump technology. A conventional three-source, SO-8 package is constructed using wire-bond technology. The bottomless package simultaneously eliminates the wire-bonds and allows the PCB heatsink to be in direct contact with the solderable backside of the MOSFET die. The new package reduces the junction-to-case thermal resistance below 0.5 degrees C per watt, and has a lower thermal resistance than the D2-pak, with a footprint of only 30mm². Fairchild also offers the bottomless SO-8 package in a seven-source pin-out that provides up to 1mW lower RDS(on) versus the standard three-source SO-8.

Samples and production quantities are available now, with lead times of eight weeks or more for larger orders.