8:1 analog multiplexer with sub-4Ω on-resistance
The MAX4638ESE+ from Analog Devices is a single 8:1 multiplexer/demultiplexer (MUX) that switches one of eight inputs to a common output. Its 3.5Ω max on-resistance keeps signal attenuation low in precision analog paths, and the 100mΩ channel-to-channel matching minimizes gain errors between selected channels. Switching is fast — 18ns max turn-on, 7ns turn-off — so it can handle multiplexed ADC front-ends without introducing aperture delay.
Signal integrity specs that matter for the BOM
With a -3dB bandwidth of 50MHz and crosstalk of -85dB at 1MHz, the MAX4638ESE+ preserves signal fidelity when multiplexing audio, sensor, or low-frequency RF paths. The 13pC charge injection means less glitch energy when switching between channels — important for sample-and-hold or precision DAC reference switching. The off-channel capacitance is 9pF (source) and 40pF (drain), which sets the settling time trade-off when driving high-impedance loads.