부산대학교 도서관

According to this invention, a level converter has a pair of differential transistors operated at a negative voltage in accordance with an ECL-level input signal, and first and second output nodes are arranged between a collector of one transistor of the pair of differential transistors and a positive power source voltage. A level-converting resistor for converting an ECL-level signal to a positive level signal is inserted between the first output node and the second output node so as to output the positive level signal in accordance with an ECL-level input signal to the first output node. The emitter-collector path of a bipolar transistor is inserted between the second output node and the positive power source voltage. A clamp potential for controlling saturation of transistors constituting a TTL circuit connected to an output of the transistor is generated by a constant potential applied to the base of the transistor.