The OPA678 is a wideband monolithic operational amplifier with two independent differential inputs. Either input can be selected by an external TTL or ECL logic signal. The amplifier is externally compensated and features a very fast input selection speed, 4ns for either ECL or TTL. This amplifier features fully symmetrical differential inputs due to its “classical” operational amplifier circuit architecture. Unlike “current- feedback” amplifier designs, the OPA678 may be used in all op amp applications requiring high speed and precision. Low distortion and crosstalk make this amplifier suitable for RF and video applications. The OPA678 is available in plastic DIP and SO-16 packages.