DFN PACKAGE
LAYOUT GUIDELINES
The OPA277 series uses the 8-lead DFN (also known as
SON), which is a QFN package with contacts on only two
sides of the package bottom. This leadless, near-chip-scale
package maximizes board space and enhances thermal and
electrical characteristics through an exposed pad.
The leadframe die pad should be soldered to a thermal pad
on the PCB. Mechanical drawings located at the end of this
data sheet list the physical dimensions for the package and
pad.
Soldering the exposed pad significantly improves board-level
reliability during temperature cycling, key push, package
shear, and similar board-level tests. Even with applications
that have low-power dissipation, the exposed pad must be
soldered to the PCB to provide structural integrity and long-
term reliability.
DFN packages are physically small, have a smaller routing
area, improved thermal performance, and improved electrical
parasitics, with a pinout scheme that is consistent with other
commonly-used packages, such as SO and MSOP. Addition-
ally, the absence of external leads eliminates bent-lead
issues.
The DFN package can be easily mounted using standard
printed circuit board (PCB) assembly techniques. See Appli-
cation Note, QFN/SON PCB Attachment (SLUA271) and
Application Report, Quad Flatpack No-Lead Logic Packages
(SCBA017), both available for download at www.ti.com.
The exposed leadframe die pad on the bottom of the
package should be connected to V–.
OPA277, OPA2277, OPA4277
SBOS079A
11
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