1606/1646 OutSmarts Balanced Line Driver ICs THAT Corporation 1606/1646 OutSmarts Balanced Line Driver ICs are monolithic audio differential line drivers. The devices offer improved performance over conventional cross-coupled designs. 1606/1646 are based on high-performance, fully differential opamps, and laser-trimmed thin-film resistors. Both families exhibit low noise and distortion, high slew rate, and wide output swing. The parts are stable when driving difficult loads, and have short-circuit protected outputs.