Quad SPST-NO switch with 4 Ohm on-resistance
The MAX4605CSE+ is a quad single-pole single-throw normally-open (SPST-NO) analog switch from Analog Devices, built for precision signal routing in test equipment, data acquisition, and audio switching applications. Each of the four independent switches is a 1:1 multiplexer/demultiplexer with a maximum on-resistance of 4 Ohm, channel-to-channel matching of 200 mOhm, and switching times of 120 ns (ton) and 130 ns (toff) — fast enough for multiplexing sensor signals or audio line-level paths without introducing audible zipper noise.
Supply voltage and signal integrity
Crosstalk is rated at -60 dB at 1 MHz, meaning a signal on one channel couples into an adjacent channel at roughly 0.1 % amplitude at that frequency — acceptable for 16-bit systems below 100 kHz, but worth derating for higher-speed multiplexing. Charge injection is 225 pC typical; when the switch opens, that charge spike couples into the load capacitance. For a 100 pF sample-and-hold cap, the injected charge creates a 2.25 V glitch — the downstream ADC's acquisition time must settle this before conversion. Leakage current in the off state is 500 pA maximum at 25 °C, and channel capacitance is 34 pF (both source and drain off). These keep the signal path high-impedance when the switch is open, preserving accuracy in high-impedance sensor front-ends.
The 16-SOIC footprint is common and rework-friendly with standard hot-air profiles.