An apparatus includes, an Integrated Circuit (IC), first electrical connections and second electrical connections. The IC is mounted on a substrate and is configured to exchange one or more communication signals with one or more electro-optical transducers, and to exchange one or more control signals with external circuitry. The first electrical connections extend from the IC on a plane parallel to the substrate, and are configured to conduct the communication signals. The second electrical connections extend from the IC on one or more planes not parallel to the substrate, and are configured to conduct the control signals.