  We report on the design of a serializer ASIC to be used in the ATLAS forward
muon detector for trigger data transmission. We discuss the performance of a
prototype chip covering power dissipation, latency and stable operating line
rate. Tests show that the serializer is capable of running at least at 5.76
Gbps with a bit error ratio below 1x10^{-15}, and a power consumption of 200 mW
running at 4.8 Gbps. The latency between the start of loading 30 bits into the
serializer to the transmission of the first bit from the serializer is measured
to be about 6 ns.
