The PS398/PS399 are improved high precision analog multiplexers. The PS398, an 8-channel single-ended mux, selects one of eight inputs to a common output as determined by a 3-bit address A0-A2. An EN (enable) pin when low disables all switches, useful when stacking several devices. The PS399 is a 4-channel differential multiplexer. It selects one of four differential inputs to a common differential output as determined by a 2-bit address A0, A1. An EN pin may be driven low to disable all switches. These multiplexers operate with dual supplies from +3V to +8V. Single-supply operation is possible from +3V to +15V. With +5V power supplies, the PS398/PS399 guarantee <100 on-resistance. On-resistance matching between channels is within 6. On-resistance flatness is less than 11 over the specified signal range.