8:1 analog switch with mil-temp range
The Texas Instruments CD4051BMG4 is an 8-channel analog multiplexer/demultiplexer — one common I/O routes to any of eight independent channels, or the eight channels demux a single input to eight outputs. The 8:1 topology handles both directions symmetrically, so a single part replaces a mux or a demux depending on signal flow. On-state resistance is 240 Ohm maximum, which is the figure to use for worst-case insertion loss and voltage divider calculations. Channel-to-channel matching holds within 5 Ohm, so gain errors across the eight paths stay tight. The -3 dB bandwidth of 20 MHz means the switch passes signals up to the low-MHz range with minimal attenuation — adequate for audio, baseband video, and low-speed IF or data acquisition paths.
Supply rails and signal headroom
Single-supply operation covers 3 V to 20 V, and dual supplies span ±2.5 V to ±9 V. With dual rails, the analog signal can swing symmetrically around ground without a DC bias — useful for bipolar sensor inputs or audio paths. The single-supply range also lets the part run from common 5 V or 12 V logic rails. Leakage current off-channel is 100 nA maximum, which sets the floor for crosstalk and charge injection in high-impedance circuits. Channel capacitance measures 0.2 pF on the source side and 30 pF on the drain side — the larger drain capacitance loads the common bus and limits settling time when switching between channels.
Temperature grade and deployment
That qualifies the part for avionics, satellite payloads, downhole instrumentation, and any sealed or outdoor system where the ambient swings beyond industrial limits. The 16-SOIC package is surface-mount with a 0.154-inch body width, standard for automated assembly.