PCA2131 exposed pad connection

[mbabic123]

In PCA2131 datasheet rev. 1, exposed pad is preferred to be tied to Vss. In PCA2131 datasheet rev. 2.1, exposed pad is however recommended to be left floating. What is the consequence if exposed pad is connected to Vss, as in original recommendation?

[guoweisun]

 It should be noted that the exposed pad is not intended to enhance or promote thermal or electrical performance.

If you has not seen any misbehavior from previous recommendation on previous designs, then it is OK, but it is recommended (from quality team) for them to start screening for shorts on exposed pad to other pins.

For new designs (and those able to still change layout) recommend customer to change their design to follow new recommendation.