The AD606 is a complete demodulating logarithmic amplifier.As such it incorporates successive detectionstages, a dc feedback section to null out the input offsetvoltage, a current summer to add up the logarithmic currentoutputs of the stages, and a low pass filter for thelog output to remove the carrier from the demodulatedsignal. The latter, while offering useful integration forsome lower speed systems, slows down the response ofthe logarithmic output in high speed systems. It is thereforedesireable in high speed systems to bypass this filterand realize the faster response.