EL2082 pdf datasheet (Current

The EL2082 is a general purpose
variable gain control building block,
built using an advanced proprietary
complementary bipolar process. It is a two-quandrant
multiplier, so that zero or negative control voltages do not
allow signal feedthrough and very high attenuation is
possible. The EL2082 works in current mode rather than
voltage mode, so that the input impedance is low and the
output impedance is high. This allows very wide bandwidth
for both large and small signals.
The IIN pin replicates the voltage present on the VIN pin;
therefore, the VIN pin can be used to reject common-mode
noise and establish an input ground reference. The gain
control input is calibrated to 1mA/mA signal gain for 1V of
control voltage. The disable pin (E) is TTL-compatible, and
the output current can comply with a wide range of output
voltages.