Frequency converters and translators scale and/or filter frequency inputs to produce outputs signals with frequencies that are a function of the inputs. Differential analog inputs, bandwidth, accuracy, and signal isolation are the most important device specifications to consider when searching for frequency converters and translators.  Differential channels use the difference between two signals as an input; common mode is filtered out. In some systems, differential inputs are combinations of two single-ended inputs; in this case, twice the number of differential channels would be available as single-ended inputs.  Bandwidth is the difference between the high and low limits of the frequency response, typically defined by a variation from a nominal value by a stated value such as 3 dB.  Accuracy depends on the signal conditioning linearity, hysteresis, temperature considerations, etc. It is represented here as percent full scale of measurement range.  Signal isolation is the separation of any direct electrical contact of a signal. This can be done in various ways including optical isolation, capacitors, and magnetic induction.