An isolator provides bidirectional data transfer for a plurality of communications channels. First and second dies are located on first and second sides of a voltage isolation barrier and have a first and second plurality of digital data input/output pins associated therewith. First circuitry on the first die and third circuitry on the second die serializes a plurality of parallel digital data inputs from the digital data input/output pins onto one link across the barrier and transmits synchronization clock signals associated with the digital data inputs over a link across the barrier. Second circuitry on the second die and fourth circuitry on the first die de-serializes the digital data inputs from the first link onto the second digital data input/output pins and receives the first synchronization clock signal associated with the digital data inputs on the second link.