transmission line through a series matching resistor, which attenuates the output by a factor of 2); in some cases you set the gain with an external resistor pair. An example of the latter is the AD8174 4-input multiplexer, with a bandwidth of 270 MHz at gains of +1 or +2 (at higher gains the bandwidth drops, e.g., to 55 MHz at G=+10).Capacitance from input to output causes signal coupling in an OFF switch, rising at high frequencies. shows the effect for the popular DG211 and DG411 series.circuits, but much lower than normal for low-frequency signals, for which a typical load impedance is 10k or more. Even with a 50 Ω?load, the feedthrough becomesIn most low-frequency applications capacitive feedthrough is not a problem. If it is, the best solution is to use a pair of cascaded switches or, better still, a combination of series and shunt switches, enabled alternately. The series cascade doubles the attenuation (in decibels) at the expense of additional RON, whereas the series-shunt circuit.