|Name||WSON (Plastic Small-outline No-lead Package)|
|Variants||Varying number of pins.|
|Pin Count||8 (all also have exposed thermal pad)|
|Pitch||Varies. Many are 1.27mm (just like SOIC, for example the Cypress WSON 8L package), the TI DMB package as a pitch of 1.0mm, and the TI DQD package as a pitch of 0.4mm.|
|Solderability||Hard to solder with a soldering iron due to underside thermal pad.|
The WSON package has a exposed thermal pad on the underside. However, it is not normally electrically connected to anything, and is optionally soldered to the PCB. It is recommended to be soldered when the PCB has a large amount of flex, else left unconnected.
Below is an “odd shaped” SON package used by Numonyx flash chips that goes under the name VDFPN8. Notice the half-round appearance of the pins.
Atmel produces a document titled PCB Design Considerations when Changing from 6-pin SOT23 to 6-pin WSON Atmel Products. It is a good read if you are migrating from larger SOT-23 packages to the smaller WSON package.
The DMB/PWSON Package (Texas Instruments)
DMB package (also called
PWSON) is a variant of the
WSON package used by Texas Instruments. It has a pitch of 1mm. The HDC1080 datasheet is an example of a TI component which comes in the
The DQD Package (Texas Instruments)
DQD package is a variant of the
WSON package used by Texas Instruments. The TPD8F003 datasheet is an example of a TI component which comes in the
3D model exist for some of the DQD packages on 3DContentCentral, for example:
- SOIC Component Package
- TO-236AA Component Package
- TO-236AB Component Package
- SMT3 Component Package
- SOT-346 Component Package