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 gaincontrol 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, or 1 V into a 100 load.