Quad SPDT switch for precision signal routing
The MAX333EWP+T integrates four independent SPDT switches on a single die, each configurable as a 2:1 multiplexer or demultiplexer. With a maximum on-resistance of 250 ohm, the switch adds a predictable series resistance that must be factored into the signal-path attenuation budget — particularly in precision analog front-ends where the voltage divider formed by R_on and the load impedance can introduce gain error.
Signal integrity and switching performance
Crosstalk is specified at -78 dB at 1 MHz, meaning the feedthrough from one channel to another is roughly 80 dB below the signal level — adequate for 12-bit to 14-bit multiplexed systems switching at moderate frequencies. Channel capacitance (CS(off), CD(off)) is 5 pF, which together with the on-resistance forms a low-pass corner near 127 MHz; for sub-1 MHz analog signals the roll-off is negligible. Maximum switching times are 1 µs turn-on and 500 ns turn-off, fast enough to support sample rates up to several hundred kilohertz without introducing timing skew between channels. Off-leakage current is 5 nA maximum, so the switch does not load the signal source appreciably when the channel is deselected — important for maintaining accuracy in high-impedance sensor interfaces.
The supplier device package is listed as 20-SOIC, matching the package / case dimension. Tape & Reel and Cut Tape options are available for prototyping or volume reflow.
