The differential gain control interface allows the use of either differential or single-ended positive or negative control voltages. Several of these amplifiers may be cascaded and their gain control gains offset to optimize the system S/N ratio. The AD603 can drive a load impedance as low as 100 with low distortion. For a 500 load in shunt with 5 pF, the total harmonic distortion for a 1 V sinusoidal output at 10 MHz is typically -60 dBc. The peak specified output is 2.5 V minimum into a 500 load.