Various circuit techniques for implementing ultra high speed circuits use current-controlled CMOS (C.sup.3MOS) logic fabricated in conventional CMOS process technology. An entire family of logic elements including inverter/buffers, level shifters, NAND, NOR, XOR gates, latches, flip-flops and the like are implemented using C.sup.3MOS techniques. Optimum balance between power consumption and speed for each circuit application is achieve by combining high speed C.sup.3MOS logic with low power conventional CMOS logic. The combined C.sup.3MOS/CMOS logic allows greater integration of circuits such as high speed transceivers used in fiber optic communication systems.

In one example, a current-mode logic (CML) circuit includes a differential transistor pair having a differential input port configured to receive a differential input voltage, a bias port configured for coupling to a current source, and a differential output port. The CML circuit further includes a load circuit coupled to the differential output port. The load circuit includes an active inductive load, a cross-coupled transistor pair, and a switch coupled between the cross-coupled transistor pair and the differential output.

In some implementations, the device may include a first circuit receiving an input signal having a first frequency, the first circuit including a first node and a second node. The device may include a second circuit receiving an input signal having a second frequency different from the first frequency, the second circuit including a first node and a second node, a first inductor coupled between the first node of the first circuit and the first node of the second circuit. The device may include a second inductor coupled between the second node of the first circuit and the second node of the second circuit, a first switch coupled between the first node of the second circuit and the second node of the second circuit, at least one differential inductor formed of the first inductor and the second inductor in response to the first switch being in a closed state.