The AD605 is a low noise, accurate, dual channel, linear-in-dB variable gain amplifier, which is optimized for any application requiring high performance, wide bandwidth variable gain control. Operating from a single +5 V supply, the AD605 provides differential inputs and unipolar gain control for ease of use. Added flexibility is achieved with a user determined gain range and an external reference input which provides user determined gain scaling (dB/V). The high performance linear-in-dB response of the AD605 is achieved with the differential input, single supply, exponential amplifier (DSX-AMP) architecture. Each of the DSX-AMPs comprise a variable attenuator of 0 dB to 48.4 dB followed by a high speed fixed gain amplifier. The attenuator is based on a 7 stage R-1.5-R ladder network. The attenuation between tap points is 6.908 dB and 48.360 dB for the entire ladder network. The DSX-AMP architecture results in 1.8 nV/Hz input noise spectral density and will accept a 2.0 V input signal when VOCM is biased at VP/2.