- Published in issue 7/1995 on page 54
Most of the new, fast current-feedback op amps have an enable input via which it is possible to switch the device on and off. Because of this, the output 'floats', so that it is permissible to couple several outputs, provided that only one op amp is active at any one time. This is a property that makes it possible to construct a multiplexer from a number of such op amps which, because of the speed of -the devices, can switch signals up to 20~30 MHz. This is ideal for video applications or, as in the present design, to multiply the number of oscilloscope inputs, for instance, to make a two-channel scope from a single-channel model.