Analog switches and multiplexers route multiple analog signals into one acquisition or output path — sensor polling, signal routing, test-channel switching. Selection is about channel structure, on-resistance and signal integrity.
Reading the Key Parameters
- Channel structure: 2:1, 4:1 and 8:1 structures in the catalog (1–3 channel groups) — fix the structure first from signal count and topology.
- Supply voltage: 2.5–5.5V single supply; signal swing must stay within the rails.
- Ron: the ~48Ω class forms a divider with downstream input impedance — budget the gain error for precision acquisition.
- Leakage: the ~1nA class; on high-impedance sources leakage converts directly into voltage error.
- Propagation delay & bandwidth: ~50ns switching delay and ~180MHz -3dB bandwidth — check margin for video/high-speed routing.
Three Steps
- Pick 2:1 / 4:1 / 8:1 by signal count and switching topology;
- Work the error budget from Ron against source/load impedance;
- Confirm signal swing stays in-rail and delay/bandwidth cover your fastest signal.
Common Pitfalls
- Signals exceeding the rails, turning on protection diodes — distortion or crosstalk follows;
- Ignoring leakage error on high-impedance sources;
- Counting channels but not Ron flatness, ending with channel-to-channel gain mismatch.
Filter in the online parametric tool; for fit questions, submit a part-number inquiry.