Dual SPDT switch with 2:1 mux topology
The MAX4526CSA+T is a dual single-pole double-throw (SPDT) analog switch from Analog Devices, configured as a 2:1 multiplexer/demultiplexer per channel. Two independent SPDT switches share the same 8-SOIC package, giving you four signal paths that can be routed between two common outputs. Each switch presents a maximum on-resistance of 175 Ohm, with channel-to-channel matching held to 500 mOhm. For a precision analog signal chain, that matching figure means the insertion loss difference between the two channels stays below 0.3% in a 10 kOhm load — negligible for most sensor or audio paths.
Charge injection and leakage for precision routing
Charge injection is specified at 1 pC typical. When the switch turns off, that 1 pC of injected charge translates to a voltage glitch on the signal line — about 77 µV into a 13 pF load. For a 16-bit ADC with a 5 V reference, that is roughly 1 LSB of error, so the part is well-suited for multiplexing signals into a precision converter without external compensation. Off-state leakage current is a maximum of 500 pA across the full temperature range. In a high-impedance sensor front-end with a 1 MOhm source, that leakage creates a 500 µV offset error — acceptable for most industrial analog inputs but worth budgeting in a microvolt-level design. Channel capacitance is 13 pF for both the source and drain pins when the switch is off. This capacitance, combined with the 175 Ohm on-resistance, sets a 3 dB bandwidth of roughly 70 MHz — more than adequate for audio, low-speed data acquisition, or configuration routing.
Supply voltage flexibility: single or dual rails
This dual-rail capability lets you route bipolar signals up to ±18 V without level shifting — useful for op-amp output multiplexing or audio crosspoint switching where the signal swings below ground. With a single 5 V rail, the switch handles signals from 0 V to 5 V. With ±15 V rails, it passes signals from -15 V to +15 V. The supply range covers common industrial rails (5 V, 12 V, 15 V, 24 V) without needing an extra regulator.