I have a CP2102N-EB evaluation board, which says Rev 2.1. Why do the BOM and schematic both say Rev 2.2?
Following board production, it became necessary to make a minor BOM change that involved populating R22 and depopulating R12 due to a limitation of the Sipex RS232 transciever when that device is communicating with another of the same device. This was BOM change only (resulting in a new revision number) and did not involve any changes to the board itself (so the boards has the older revision number).
Because of this change, however, in order to measure power of the CP2102N and achieve the lowest system power consumption, remove R22 and populate R12. This allows the Sipex RS-232 transceiver to enter shutdown mode when it is not receiving RS-232 signals. The transceiver leaves shutdown mode only when it receives RS-232 signals (+-3V) on RxIN, not digital signals on TxIN.