An integrated circuit is incorporated into a communications system to enable a channel to achieve data rates that are at least double that which are currently achievable. The integrated circuit combines serial data signals using recovered clock and serial data signals in reference and non-reference clock domains. The integrated circuit rate converts recovered serial data in one of the clock domains, performs a phase alignment at the converted data rate, and returns the rate converted and phase-aligned serial data to the recovered data rate in response to the recovered clock from the remaining clock domain. Thereafter, the recovered and aligned serial data signals are combined. The phase alignment is monitored in circuitry that detects when a threshold offset is violated. When the threshold offset is violated a synchronization circuit is enabled.