In one example, an apparatus includes an offset tunable edge slicer having an input to receive a pulse amplitude modulation signal. The offset tunable edge slicer also has a plurality of possible offset settings corresponding to a plurality of different reference voltages of the offset tunable edge slicer. A multiplexer has an output coupled to the input of the offset tunable edge slicer and an input to receive a control signal that selects one of the plurality of possible offset settings for the offset tunable edge slicer. A phase detector has an input coupled to an output of the offset tunable edge slicer.