Silicon Labs offers the WF200D RF transceiver in a few different variations. You might find an ‘R’ suffix at the end for WF200DR, spot an ‘S’ in front of the D for WF200SD, or both. What do these digits call out?
The “R”, in this case, is a simple reel packaging callout indicating the part ships on a reel. The ‘R’ versions of the part are identical to non-‘R’ versions.
The “S”, per the supplier’s datasheet, indicates the existence of a secure link interface for applications requiring higher information security. This product is different from non-‘S’ products, and the two cannot be dropped in interchangeably with each other.