8:1 analog mux for precision signal routing
The MAX4051ACSE+T is a single 8-channel CMOS analog multiplexer/demultiplexer from Analog Devices, routing one of eight inputs to a common output with 100 Ohm max on-state resistance. It operates from a single 2V to 16V supply or dual ±2.7V to ±8V rails, making it suitable for mixed-voltage signal chains where the analog swing spans both positive and negative references.
Signal integrity at 100 kHz and beyond
Crosstalk is specified at -90 dB at 100 kHz — this means a signal on one channel couples into an adjacent off-channel at roughly 31.6 µV per volt of signal, which is low enough for 12-bit to 14-bit data acquisition systems scanning multiple sensor inputs. Charge injection is just 2 pC typical, so when the mux switches between channels, the glitch injected into the signal path is small — important for sample-and-hold circuits or high-impedance ADC front-ends where settling time matters. On-resistance matching between channels is 6 Ohm max, and channel capacitance is 2 pF (both CS(off) and CD(off)), keeping the RC time constant consistent across all eight paths and minimising harmonic distortion in audio or low-frequency AC applications.
Switching speed and leakage at the bench
Maximum turn-on time is 175 ns and turn-off is 150 ns, so the mux can switch channels at rates up to roughly 3 MHz before the settling window closes — well within the needs of a multiplexed SAR ADC running at 500 kSPS. Off-channel leakage current is 100 pA max at 25°C, meaning the mux will not load down the signal source when deselected — a practical advantage when scanning high-impedance outputs like pH probes or thermocouple amplifiers.