What this 8:1 analog mux does on the board
The NX3L4051PW,118 is an 8:1 analog multiplexer/demultiplexer from NXP, built to switch one common I/O to any of eight channels with a 750mOhm max on-state resistance. That low Ron means minimal signal attenuation and voltage drop in precision analog paths — audio, data acquisition, or sensor front-ends where a few milliohms of series resistance would shift the reading.
Key parametrics that decide the fit
Crosstalk is -90dB at 100kHz — that is low enough to keep a 100kHz signal on channel 0 from bleeding into channel 1 at a level that matters for a 12-bit ADC. Charge injection is 15pC, which translates to a millivolt-level glitch on a 10pF sampling cap; the downstream sample-and-hold settles it within one conversion cycle. Switching times are 45ns on, 25ns off — fast enough for 15MHz -3dB bandwidth analog signals. The 35pF off-channel capacitance means the mux does not load the source significantly when the channel is deselected.
Housed in a 16-TSSOP (4.40mm width) with surface-mount termination. The 0.65mm pin pitch is standard for two-layer boards; the narrow body keeps the routing length short between the mux and the ADC or op-amp.