An ISL clamped NPN transistor and a PNP interface transistor are merged together in a single semiconductive isolation island. The two transistors are laterally separated from each other along a semiconductive surface of the island, which also includes one or more metallic elements forming individual Schottky barrier contact diodes with the semiconductive surface. The PNP transistor provides translation between an ISL logic gate and a TTL logic gate. One of the Schottky diodes may be used in combination with the NPN transistor as an active pulldown for an output transistor of the TTL logic gate.